Israeli troops took over most of Palestinian Authority President Yasser Arafat's Ramallah compound on Friday, fighting room-to-room and arresting as many as 70 people, Israel Defense Forces said. The Palestinians disputed the number of arrests, but said one Arafat aide had been arrested at a home outside the compound. One of his aides said Arafat was holed up in an office on the second floor of a building. He has been confined to Ramallah by Israel since December. Also on Friday, Al Aqsa Martyrs Brigades -- the military wing of Arafat's Fatah movement -- claimed responsibility for the blast that killed at least two Israelis in Jerusalem.