BUJUMBURA, Aug 16 (Reuters) - Burundi rebels asked on Thursday for a meeting with South African mediators before they could return to a truce monitoring team they quit last month in a move that sparked fears of renewed violence. Senior members from the Hutu Forces for National Liberation (FNL) have disappeared from the central African country's capital, Bujumbura, and many Burundians believe they may have returned to the bush. "We want a meeting between the leader of the movement Agathon Rwasa and chief mediator Charles Nqakula to see how all the obstacles to the implementation of the ceasefire agreement can be sorted out," said FNL spokesman, Pasteur Habimana. "If the mediator gives us a guarantee about the security of our members and if there is an agreement on the release of our war and political prisoners, FNL members will immediately join the joint ceasefire monitoring team." Ethnic conflict in Burundi has killed 300,000 people over the last 10 years and the FNL insurgency is seen as the final barrier to lasting peace in the country of seven million. The ceasefire monitoring team was set up after the FNL signed a peace deal with the government in September. It comprised FNL members, government officials and South African mediators and began its mandate in February. But its work was repeatedly delayed by wrangling. The rebels quit the team for the second time last month, accusing the government of refusing to withdraw its troops from areas under their control and asking for more talks on the roles they would play once assimilated into a new national army and police. Habimana said the mediator met some FNL officials in Dar es Salaam on Monday and told them that December 31 was the deadline for talks between the FNL and the government. "He urged us to move fast so that we finish the implementation of the peace deal by the end of December," he said in a telephone conversation from Dar es Salaam. "We are ready to respect his recommendation, but first we want him to meet the chairman of our movement."