KIGALI -- Sixty teenaged Tutsi boys were abducted by Hutu militia from a church complex in the Rwandan capital Kigali on Tuesday and butchered, a United Nations official said Wednesday, quoting Tutsis who evaded capture. France and its European and African allies are prepared to intervene militarily in Rwanda if massacres continue and a cease-fire is not respected, Foreign Minister Alain Juppe said Wednesday. He said intervention would take place "relatively soon if we learn of new massacres in the coming days. "If massacres continue and if the cease-fire is not respected," he said, "France, along with its European and African partners, is prepared to launch a ground intervention to protect groups threatened with extinction." In the massacre by Hutu militia, UN military spokesman Major John-Guy Plante said the Tutsis saw a total of 60 boys taken away from the Saint Paul church and killed near a bridge at a spot called Rugenge in a government-held part of the city. Six Tutsis, who said they fled the complex Tuesday night after seeing the teenagers abducted, appealed for help to the international community in a letter obtained by Reuters. The six, hiding in a Kigali hotel, said the abductions were carried out on the orders of a local government administrator they did not name. The letter, addressed to the commander of the UN Assistance Mission in Rwanda, or UNAMIR, Major-General Romeo Dallaire, begged UNAMIR "to do all in its power to prevent the imminent execution of a plan of massacre threatened against us." The letter was copied to the UN Secretary-General, U.S. President Bill Clinton and other world leaders and human rights groups. It said almost 300 of the 4,000 people seeking shelter in the complex had been abducted and killed since the massacres erupted in Rwanda on April 6. Militia made three separate raids on the complex on April 16, 22 and 24, the Tutsis said. Since then, refugees in the complex had been subjected to constant threats and lived in fear. "These swine are still thirsty for human blood," the letter said. Mortar exchanges and small arms fire rocked the capital Wednesday despite the promise of a cease-fire between the two warring sides being declared at an African summit in Tunis. Rwanda's interim president said Wednesday his government would strictly observe the cease-fire agreement with rebels of the Tutsi-dominated Rwanda Patriotic Front and had the means to stop the massacres. "We have made a formal undertaking and we call on the population to respect it," Theodore Sindikubwabo said at an Organization of African Unity summit in Tunis. The RPF representative at the summit, senior politburo member Pasteur Bizimungu, agreed to the cease-fire Tuesday night. It was due to take effect Wednesday after an announcement by leaders attending the OAU meeting.