Israel has imposed a ban on Palestinian travel in the West Bank and Gaza Strip until after Tuesday's general elections.
Israel's army said the ban is in response to warnings about planned attacks against Israeli citizens by Palestinian militant groups.
The move comes on the heels of an overnight Israeli military raid in Gaza City that Palestinians say killed 12 people and wounded at least 50 others.
Palestinians say Israeli tanks and armored vehicles backed by helicopter gunships moved into Gaza City late Saturday from three directions, coming within a kilometer of Palestine Square in the center of town. The Israelis left Gaza City several hours later, after intense firefights with Palestinians.
It was the deepest incursion into the Gaza Strip's main population center since the Palestinian uprising began 28 months ago.
The raid came as U-S Secretary of State Colin Powell -- speaking Sunday at the World Economic Forum (in Davos, Switzerland) -- said a Palestinian state is possible by 2005.
Mr. Powell said the United States will be engaged in the coming months and years in trying to resolve the Middle East conflict.
Mr. Powell also renewed President Bush's call for Palestinians to choose new leadership and urged Israel to do its part in generating trust by easing restrictions in the Palestinian territories, and ending construction of Jewish settlements there.