21.   On Sunday, the United Nations issued a written ultimatum, saying it would authorize NATO airstrikes if the Serbs attacked the Dutch peacekeepers.

22.   On Sunday, the United Nations warned it would authorize NATO airstrikes if the Serbs attacked the Dutch peacekeepers.

23.   On Sunday, the United Nations said in writing it would authorize NATO airstrikes if the Serbs attacked the Dutch peacekeepers.

24.   Several nations are concerned that if the embargo is lifted, the Bosnian Serbs might attack U.N. peacekeepers.

25.   The government and political party leaders have also appealed to the students Tuesday to demonstrate peacefully and not to attack U.N. peacekeepers.

26.   The group has often been accused of attacking Russian peacekeepers.

27.   The United Nations had warned on Sunday that it would authorize NATO airstrikes if the Serbs attacked the Dutch peacekeepers.

28.   The United Nations spoke of a skirmish that occurred after government soldiers attacked British peacekeepers.

29.   The U.N. also fears the peacekeepers will be attacked if the United States carries through its threat to lift the international arms embargo on the Bosnian government.

30.   Tuesday evening, rebel fighters attacked U.N. peacekeepers in the northwestern town of Port Loko, U.N. spokesman David Wimhurst said.