Four NATO peacekeepers and six Serb protesters were wounded Tuesday when violence erupted at a disputed crossing point between Serbia and Kosovo, officials said. "Four KFOR soldiers are wounded by pipe bomb (an improvised explosive device). One of them badly and three slightly," KFOR deputy spokesman Kai Gudenoge told AFP. Meanwhile the director of a hospital in nearby Kosovska Mitrovica told local media that six Serb protestors who clashed with KFOR at the disputed Jarinje border post were seriously injured by gunfire.