Hutu extremists had just attacked her village, killing her husband and other villagers who dared to shun the rebellion to overthrow Rwanda's Tutsi-dominated government. ``They accused us of collaborating with the Tutsis, so we fled to that camp," she said.

The camp, though guarded by soldiers, was no safer.

Last month, rebels attacked the Hutu refugees encamped in Kayove, a town of tea farmers. Ntiruhongwera's home - a tent of plastic tarpaulins - offered little resistance. Her three oldest children were hacked to death. The youngest, an 18-month-old girl, was shot dead while strapped to her mother's back as Ntiruhongwera fled.

``They were singing: `We are the army of Jesus,' " said Ntiruhongwera, 28, recovering in Gisenyi Hospital from a bullet that shattered her left arm. ``They asked people to join them or die."

Their chant made no sense to Ntiruhongwera, but not much makes sense in Rwanda these days. The 100-day genocide that left at least half a million Rwandans dead ended four years ago. But the horror continues - different only in scale from the bloodbath of 1994.

Instead of wholesale national slaughter, there are lesser but persistent bursts of murder and terror now. Neighbors kill neighbors, women and children are not spared, and one massacre so quickly follows another - 10 dead here, 15 there - that one tragedy hardly registers before another supplants it.

The U.S.-backed government denies that this is a civil war, but there is not much else to call it. Tens of thousands of people have been murdered since the end of the 1994 genocide; human rights groups say the killings are so frequent that they can't keep an accurate death total. A quarter of the nation is virtually a no-go zone for civilians. International aid workers can't move without military escort.

The attack on the camp at Kayove, like most of the organized killings that penetrate deep into the lush countryside, seemed designed to instill terror and undermine government support among villagers. Such murders play out on a lesser scale now than in 1994, but each death is just as brutal - and all the more horrifying to a nation that once dared hope the genocide was over.

The Kayove attack bore disturbing similarities to the 1994 slaughters. No effort was made to spare women and children. In fact, several witnesses in Kayove said women and children were among the killers, directed by uniformed soldiers. The children were armed with hoes and machetes and told to kill other children, the witnesses said.

Once Ntiruhongwera's arm heals, she said, she will return to the camp where her children were murdered. ``There's no other options," she said wearily.

More than four years after the end of the 1994 genocide, there is truly no place to hide in Rwanda, for those who kill are rarely strangers.

``The infiltrators are among the people, so they know where they are every day," said Dr. Leon Ngeruka, director of medicine at the 300-bed Gisenyi Hospital, who sees a steady flow of civilian casualties.

The same Hutu extremists who engineered the 1994 massacres are trying to retake control of the country they lost that year, when a Tutsi-led army put an end to the genocide. The killings are most widespread in northwest Rwanda, which has grown increasingly unstable since a million Hutu refugees returned in late 1996 and early 1997 from camps in surrounding countries.

This part of Rwanda, which shares a mountainous volcanic border with Congo and Uganda, remains the stronghold of the Hutu extremists. The rebels are targeting the few Tutsis who remain, as well as Hutus who balk at collaborating with the rebels.

Despite millions of dollars in international aid poured into Rwanda to build a justice system and establish institutions that de-emphasize ethnic differences, the country remains bitterly divided.

``Ethnic tension is worse now than it was two years ago," said a human rights worker who has been in Rwanda since 1994.

In many northwest villages, the Rwandan military seems like an occupation army. International aid workers, frightened by the killing of foreigners last year, won't venture into many areas without a military escort.

The country's richest agricultural region is largely idle; tens of thousands of rural residents have fled the fighting for camps or to stay with relatives in the city. The area around the National Park of Volcanoes, where Rwanda's famous mountain gorillas live, is cut off from nonmilitary vehicles. The four-year-old Tutsi-led government has bristled at criticism of the Rwandan Patriotic Army's counterinsurgency tactics, and its relations with U.N. agencies and international observers have deteriorated.

The government suspended field operations of the U.N. High Commission for Human Rights in May after the agency's spokesman criticized the public execution of 20 people convicted of genocide. The commission has since left Rwanda. U.N. investigators also raised questions about deaths attributed to the Rwandan military.

In June, Amnesty International blamed American-trained government troops for disappearances, which it said had become so frequent that many people did not bother to report them.

``Large-scale disappearances have occurred as soldiers of the Rwandan Patriotic Army have carried out mass arrests in the northwest," the human rights agency said. Although many Rwandan officers have received American training, the U.S. Embassy rejects any suggestion that U.S. Army Rangers training Rwandan soldiers are teaching them how to kill. Since 1994, small groups of American soldiers have periodically trained Rwandan troops in land mine removal, special operations, and small group tactics.

``They're teaching the Rwandans how not to kill," said an American official in Kigali.

The ruling government, whose officials are a mix of Tutsis and Hutus, says it is trying to defuse ethnic hatreds while giving survivors a sense of justice. The justice ministry is slogging through a caseload of more than 100,000 prisoners accused of genocide.

Perhaps it was too much to hope that Rwandans, an undemonstrative people who can recall details from the most horrific slaughters without any expression of emotion, would embrace reconciliation and set aside centuries-old unsettled scores.

The roots of Rwanda's ethnic hatred predate the arrival of European missionaries 100 years ago, when the pastoral Tutsis migrated south into the volcanic highlands of Central Africa. There, they subjugated the Hutus, an agricultural people who migrated from West Africa.

The Tutsi and Hutu lived in mutual suspicion until the arrival of Belgian colonists in the late 19th century. The Belgians entrusted the administration of their colony to the Tutsis, endowing them with a greater sense of superiority.

In 1959, as Rwanda neared independence, the Hutus rose up and ousted the Tutsi leaders. With a Hutu government in control, the state sanctioned an ideology that held the Tutsis as ``foreign invaders" and ``cockroaches" who should be sent back to Ethiopia.

Several pogroms were inflicted on Tutsis during the next three decades, including one in 1990 after the descendants of the Tutsis exiled in 1959 instigated a civil war from bases in neighboring Uganda.

When Hutu President Juvenal Habyarimana was killed on April 6, 1994, Hutu extremists launched the well-planned campaign to slaughter the Tutsis they claimed were responsible.

The genocide ended after 100 days, with the Tutsi rebels driving the Hutu extremists out of power. Most of the former extremist militias and Rwandan soldiers who had masterminded the genocide fled the country, along with a million Hutus who feared persecution from the new government.

From their refugee camps in neighboring countries, the exiled soldiers launched cross-border raids into Rwanda.

In 1996, the Rwandan government secretly supported a Zairean rebellion led by Laurent Kabila to dislodge the refugees providing cover for the anti-Tutsi militias. Kabila's rebellion eventually toppled President Mobutu Sese Seko. Under Kabila, the country was renamed Congo, and the camps were cleared.

Like a tidal wave of humanity, up to a million refugees returned to Rwanda in late 1996. The new government promised they would be treated fairly and get their property back.

Many refugees were from the northwest provinces of Gisenyi and Ruhengeri, a region of rich volcanic soil that is the traditional stronghold of Hutu extremists. At the time, Rwandan military officials said they were aware the refugees included hundreds, if not thousands, of people implicated in the genocide. But they were confident they could contain the infiltrating rebels.

Rebel activity picked up months after the refugees returned to Rwanda. Initially the violence was confined to the Congo border area. The attacks moved closer to the capital of Kigali this year. On July 12, suspected Hutu rebels hacked, shot and burned to death 34 people who had gathered in a hotel to watch the final World Cup soccer game on one of the few televisions in Tare, 22 miles from Kigali.

Although the Rwandan army has incorporated 4,000 Hutus into its ranks, its troops are stretched thin. Significant numbers are still deployed in Congo, where they have joined Congo Tutsis in rebelling against Kabila's government.

In Rwanda, human rights investigators say residents in rural areas are increasingly squeezed between the rebels and the government. The rebels leave buckets at night at peasants' houses to be filled with food - a demand they cannot easily refuse. Government troops retaliate against anybody with a bucket on their doorstep, whether it is filled or not.

The rebels have an intricate system of eyes and ears in their area. Rwandan military officials say the rebels use youths as couriers and porters - mainly press-ganged children who know the area well and can evade government troops.

Many rural Rwandans say they don't know the rebels, but they know they are watching. During a recent visit by Vice President Paul Kagame to a town in Gitarama province that had just been attacked, a local official made a speech supporting the government's efforts. Two days later he was murdered, presumedly by rebels.

A sense of suspicion pervades much of the country. There is hardly any traffic on the dirt road that connects Kibuye and Gisenyi provinces in western Rwanda, passing dark forests along the shores of Lake Kivu and green hillside tea plantations. In other parts of Rwanda, children wave at strangers in passing cars. Here, villagers only stare.

There are few soldiers in villages along the road, except for a hamlet of new houses built for Tutsis displaced by the repatriation of Hutu refugees in 1996. The new residents are cutting down the Gishwati Forest for farmland - and to reduce cover for the rebels.

In Kivumu, the burned carcass of a pickup truck sits along the road. A week before, rebels mounted a daylight attack on the truck, which belonged to a Chinese road-building company. Then the rebels attacked the town, killing a government agronomist and a municipal official.

There were no soldiers visible in Kivumu.

Two nights later, the rebels attacked the student dormitories at Trinity School, operated by the Roman Catholic Church. The attack came about two weeks after photocopied pamphlets mysteriously appeared, warning students to stop attending classes.

More than a dozen ethnic Hutu rebels arrived at 2 a.m. on a Monday in May at the dormitories where 21 students slept. The rebels called out the names of staff and said they wanted food. They also had a message:

``We told you to stop going to school and you didn't," the rebel leader told the teenagers, witnesses recalled. ``Now we're going to give you what you deserve."

The rebels fired first into the boys' dormitory, the bullets ricocheting off the concrete floor as students scrambled among their bunks for cover. Then they fired into the girls' dormitory. Some students attempted to flee and were cut down in the grass with machetes.

A few people climbed up and hid in the dorm's plywood ceilings, including Jerome Musonera, 20, who worked in the dormitory's kitchen.

``I'm scared now because they killed many people, and I survived," Musonera said the day after the attack as he sullenly mopped up puddles of blood mixed with scattered papers and belongings.

When the rebels were done, 11 students ages 12 to 17 lay dead. Two adult staff members also were killed.

The rebels accomplished their goals. The school was shut down, and their authority was exerted.

The day after the attack, Kivumu was once again calm, and once again patrolled by government soldiers.

Jean Damascene Kanzeguhera, a teacher at Trinity School, said Kivumu had become increasingly insecure since the refugees returned in 1996.

``Many people are farmers, so they can't leave," he said. ``Anybody who has money has already gone."

The rebels usually attack when there is no military in town. ``If they attack, all we have is our feet," Kanzeguhera said.

No local officials dared speak to visitors about the killings at Trinity School. Too many eyes were watching. They referred all questions to the next official up the hierarchy, in the next town or in the provincial capital.

``The army tries to provide security, but they can't," Kanzeguhera said. ``The army can come here and stay for a month and nothing happens. The day after they go away, it starts again."