PRISTINA, Serbia, July 3 (Reuters) - The United Nations is considering banning the use of rubber bullets in peacekeeping operations after the killing of two protesters in Kosovo, U.N. police in the province said on Tuesday. Two ethnic Albanian protesters were killed in clashes with police in February when they were shot in the head at close range by Romanian U.N. police using Italian-made rubber bullets. The bullets were manufactured in 1991 and had a shelf life of three years. A police report said they had "probably hardened" with age. Commissioner Richard Monk, U.N. police chief in the breakaway Serbian province, said he had requested that the United Nations withdraw rubber bullets from the armoury of any state supplying police units. "It remains now for the U.N. Department of Peacekeeping Operations to be supported in a final decision to prohibit such weapons in all U.N. peacekeeping missions," he told a news conference. A U.N. police report in April blamed a Romanian contingent of the 1,300-strong U.N. force for the deaths. It said there was "reasonable suspicion that such shooting was criminal". But charges could not be brought because the investigation had not identified which of the officers fired the fatal shots. Bucharest replaced the contingent in March, despite a U.N. request for 11 officers to stay on pending the inquiry. The deaths shocked Kosovo and fueled fears of unrest. Russia has blocked a Western-backed plan to give the Albanian majority province independence at the U.N. Security Council. Kosovo has been run by the United Nations since 1999, when NATO bombed to drive out Serb forces and halt the killing of Albanian civilians in a two-year war with guerrillas.