Gunfire erupted at the Gaza-Egypt border on Monday, following stone-throwing clashes between Egyptian border guards and Palestinians, witnesses said, and one Palestinian was killed. It was the most serious outbreak of violence on the border since Hamas militants blew down the border wall on Jan. 23. Egyptian forces reclosed the border on Sunday. A 42-year-old Palestinian was killed and six people were wounded by gunfire, said a Gaza health official, Dr. Moaiya Hassanain. Egyptian forces fired live bullets at the crowd, wounding several, witnesses said. Bullets landed close to an AP staffer on the Gaza side of the border. Later, Palestinian gunmen fired back. It was not immediately clear if the gunmen were from Hamas. Police from Hamas were next to the border at the time. After the clash, four vehicles with Hamas police drove in to break up the crowd, using sticks to push people away from the border. The tensions began when the Egyptian guards sealed the border hermetically Monday, not even allowing Egyptians and Gazans who had found themselves on the wrong side of the border to return home. Eyewitnesses said anger boiled over in the late afternoon as people on both sides waited for permission to cross over. Hamas policemen in the area encouraged people in the area to throw rocks at the Egyptians. Youths began pelting an Egyptian command post in the area, and forces there first threw stones back, and then fired tear gas. Medics said 26 people were treated for tear gas inhalation. Egyptian security officials in nearby El-Arish said Egyptian officers fired in the air, and there were several wounded. In Cairo, an official said there was a heavy exchange of fire. The officials spoke on condition of anonymity because they were not authorized to disclose details to the media. The Egyptian troops closed the border on Sunday, using metal spikes and barbed wire, ending a 12-day breach that had allowed hundreds of thousands of Gazans to visit Egyptian border towns.