At least five Palestinians are dead and dozens wounded after Israeli tanks moved into Palestinian-controlled territory in the Gaza Strip.

Israeli armor, carrying troops looking for militants, rumbled into Palestinian-ruled areas of the Gaza Strip.

In northern Gaza, tanks firing heavy machine guns rolled into the town of Beit Hanoun. A Palestinian policeman was killed during the incursion, and several Palestinians who threw rocks at the tanks were also shot and killed.

The tanks took up positions in Beit Hanoun, and soldiers ordered residents to stay in their homes.

At the southern end of the Gaza Strip, the Israeli army says, a Palestinian militant carrying grenades tried to infiltrate the Jewish settlement of Gush Katif. He was shot and killed by soldiers guarding the settlement.

The Israeli actions were similar to wide-ranging sweeps on Friday in the West Bank and Gaza, in which eight Palestinians were killed and about 50 arrested.

Israeli government spokesman Ra'anan Gissin has said the military will continue to launch raids to crack down on militants because, he says, Palestinian President Yasser Arafat has failed to do so.

"If he does not dismantle the mortar factories and the human bomb factories that are producing the suicide bombers, we will do it. We will do it through a sustained effort, and a sustained operation, until such time that, either the Palestinian Authority will take and assume its responsibility, or that we, ourselves, will dismantle this terrorist infrastructure. It is very simple," Mr. Gissin said.

Palestinian negotiator Saeb Erekat has said the latest upsurge in bloodshed is strengthening extremists on both sides.

"While Sharon now is busy hitting the Palestinian Authority, undermining President Arafat, declaring President Arafat as irrelevant, extremists on both sides are being strengthened, and we really need to end this cycle," he said.

The latest violence was triggered by an attack on an Israeli bus carrying Jewish settlers earlier this week. Ten Israelis were killed.

In response, the Israeli government launched widespread air strikes against Palestinian targets, and cut off all contact with Palestinian leader Yasser Arafat.

Since the Palestinian uprising against Israeli occupation broke out nearly 15 months ago, more than 1,000 people, mostly Palestinians, have been killed.