U.S. Secretary of State Colin Powell, after meeting Friday with Israeli Prime Minister Ariel Sharon, said the two had not yet reached an agreement on a schedule to end the Israeli military operation in the Palestinian territories. "We don't have a specific timetable," said Powell. But Sharon did say he hopes to conclude what he called the war against the Palestinian "infrastructure of terrorism" shortly. Powell is expected to hold a similar meeting with Palestinian leader Yasser Arafat, who has been under siege for nearly two weeks at his West Bank compound in Ramallah, on Saturday. Earlier, a senior Israeli army officer confirmed that hundreds of Palestinians had been injured or killed in the fierce fighting that accompanied Israel's incursion into the Jenin refugee camp.