'We have received reports of the massacre of 88 students yesterday in Gikongoro, a small town close to Butare (in the south),' Abdul Kabia, executive director of the UN Assistance Mission in Rwanda (Unamir), said by phone from the capital, Kigali. 'We do not know the ethnic composition of the victims, but this is an area controlled by government forces.'
Most of the estimated 200,000 killed since President Juvenal Habyarimana died on 6 April have been from the minority Tutsi tribe, victims of extremist Hutu death squads and government troops.
Mr Kabia said reports indicated carnage was going on unabated. 'We are concerned that when we gain access to more of the country, we will discover more horrible sights, more evidence of killings.'
Heavy fighting raged between rebels of the Rwanda Patriotic Front (RPF), and government forces in Kigali from daybreak yesterday. The fighting was concentrated in districts around the airport east of the city. But the International Committee of the Red Cross (ICRC) denied a Unamir report that seven people were hacked to death by machete-wielding militiamen outside the organisation's building in Kigali on Thursday.
The UN Security Council could vote shortly to send up to 5,500 African troops in phases to Rwanda to establish safe havens for civilians. But it was unclear whether the troops would be allowed to use force, how they would be financed, and whether an arms embargo would be imposed on the warring parties. Nigeria, Ghana and Tanzania have offered troops for the operation but it was not clear how many were available. South Africa's new defence force said it had also been approached.
The Gikongoro massacre came just a day after the UN's new High Commissioner for Refugees, Jose Ayala Lasso, said the government army chief of staff, Major-General Augustin Bizimungu, had promised co-operation in investigations into mass abuses.
Aid workers have said they have no evidence that the RPF, whose ranks are made up largely of Tutsis, has been guilty of any of the recent mass killings. The government that declared itself in the aftermath of Habyarimana's death and the government army have tried to dissociate themselves from the killings, but witnesses accuse soldiers of participating in the massacres, egged on by state radio and the hardline Hutu radio RTLM.
Mr Ayala Lasso also said he had secured agreements from both sides that trapped civilians would be given safe passage out.
But yesterday, Mr Kabia said Unamir peace-keepers would not yet venture to transport some 500 civilians out of the Hotel Mille Collines in a government-held part of Kigali, where they had been sent repeated death threats from the Hutu death squads. 'We have tried it once before and were stopped by the militia. We will not try again until we have the assistance of the government forces,' he said.
Thousands of civilians have been able to move out of Kigali's Amahoro sports stadium and the King Faisal hospital in areas held by the RPF, officials said.