AT sunset, the air is hazy from cooking fires in this landscape of tiny, plastic-covered huts in what the United Nations says is by far the world's biggest refugee camp.
From a small hill, a group of Rwandan refugees watch several men perform acrobatic feats, while large clusters of camp residents sit on the ground in open-air church services. Thousands of other refugees, mostly women, carry heavy jerrycans of water on their heads as they return to their huts from long lines at scarce water taps.
Because of quick action by the UN and private relief agencies, and cooperation from the Tanzanian government, relief officials say most of the estimated 250,000 to 300,000 refugees here, including some orphans, are in fairly good health.
``It could have been a lot worse,'' says William D. Novelli, executive vice president of CARE USA, after a recent two-day visit. ``I'm very pleased with what I saw.''
But for refugees, crossing the border from neighboring Rwanda does not always mean safety: There are some killers here, too, UN officials say.
Most of the refugees fled a wave of killings that began in April when Rwandan President Juvenal Habyarimana, a member of the majority Hutu ethnic group, was killed when his plane was shot down in Rwanda on April 6.
A UN report released on June 30 describes the massive wave of killings as genocide - largely preplanned and government-backed attacks by the majority Hutu ethnic group against the minority Tutsi and Hutu moderates. The report estimates at least 200,000 to 500,000 Rwandans have been killed since April.
But at least 16 refugees are also self-avowed killers, participants in the genocide, says Panos Moumtzis, regional spokesman for the UN High Commissioner for Refugees.
Most were local Rwandan officials who apparently orchestrated mass murder and even continue to kill opponents in this camp, said Jacques Franquin, field coordinator for UNHCR here. ``People are disappearing every day.''
``Our philosophical problem is how to get rid of these killers,'' says Mr. Moumtzis. ``Are we helping the Nazis of Rwanda?''
If the Security Council adopts the June 30 Rwanda report by human rights investigator Rene Degni-Segui, which cites genocide, the UN is likely to take action to remove suspected killers from the camp, possibly with the help of the Tanzanian Army, Moumtzis says.
Meanwhile, international relief agencies continue to feed refugees here and in a second camp being established nearby.
``Some people have participated in atrocities,'' says CARE's Novelli. But, he adds, ``You can not deny services to 250,000 or risk a riot'' trying to remove the suspected killers.
CARE is one of three main relief groups distributing food here, along with Concern Worldwide and the International Committee of the Red Cross.
The refugees are predominantly Hutus who say they are fleeing killings by the mostly Tutsi-backed Rwanda Patriotic Front. But many, like Jean Marie Rwasibo, a former school teacher, say they grew up and sometimes intermarried with Tutsis. Mr. Rwasibo says he cannot go back while the RPF is in his home area near the village of Muhazi.
The refugees could be here ``for months or years,'' says Roberta Gordon, director of Concern Worldwide's activities in the camp.
Most of the refugees arrived within a 24-hour period beginning on April 28, when neither the government nor the RPF were guarding a nearby bridge over the Akagera River.
Since early April, more than 10,000 dead bodies have been removed from the river and Lake Victoria, which the river empties into, says Mark Ajobe, a Ugandan in charge of the removals who works for Lutheran World Federation.
Refugees like Marie Odette Nyirabasayitsi are happy to have survived: ``I'm here with my children,'' she says. Her parents were killed in Rwanda. But she says her children are sick from eating corn, the main staple provided, along with some beans and cooking oil. Rwandans prefer beans, potatoes, and bananas, and many sell some of their corn to get these items.
But large amounts of food intended for refugees has been stolen. Truckers often siphoned off relief food purchased in Tanzania, other food has been stolen from stockpiles in the camp, and refugees have exaggerated their family size to get extra rations, officials with the UN's World Food Programme say.
Corrective measures have been taken, however, to curb cheating and theft, and a new registration system is planned. ``Everyone is trying to do their best to control'' cheating on food, says WFP's Josephine Janabi.