Fearing an explosion of ethnic violence in Burundi, the U.N. chief has called for the creation of a standby force of up to 25,000 troops to prevent a repeat of the massacres in Rwanda two years ago.

Secretary-General Boutros Boutros-Ghali made the recommendation in a report to be presented next week to the Security Council, a copy of which was obtained Friday by The Associated Press.

The Burundi government has rejected any U.N. military force, saying its presence is unnecessary despite increasing violence between ethnic Hutus and Tutsis, the same groups involved in the slaughter in Rwanda.