Israeli troops shot and killed four Palestinian men in separate incidents in and around the northern Gaza Strip.

Israel Radio reports Israeli troops shot and killed two men who managed to slip across the fenced and heavily guarded border from the Gaza Strip. They were killed as they approached a collective farm in Israel's Negev Desert. One man was shot and killed. The other died when explosives he was carrying went off prematurely. The Palestinian militant group Hamas says it sent the men.

Two other Palestinians were killed trying to plant an explosive device near the Rafiah Yam Jewish settlement in southern Gaza.

Meanwhile, Israeli Prime Minister Ariel Sharon has rejected calls from settlers to call a referendum on his plans to dismantled all Jewish settlements in Gaza. Mr. Sharon told leaders of the settlers that he already has a mandate for his actions and has no intention of -- as he puts it -- capitulating to the threats of the rabbis.

Last week a group of leading Zionist religious leaders urged soldiers to refuse to evacuate the settlements.

Settler leaders describe their meeting with Mr. Sharon as a disgrace and vow to continue their opposition to the disengagement plan and Mr. Sharon, the man who was one of the principle champions of the settler movement.

Pinhas Wallerstein describes the talks as a dialogue of the deaf and horrible and vowed to continue the fight, with or without a referendum. "With [a] referendum, without referendum we will do the best," he said. "He will lose the fight."

Mr. Sharon has said Israel cannot continue to defend the enclaves indefinitely and that Israel's security depends on a total evacuation of the settlements. The settlers say Mr. Sharon is giving in to Palestinian violence and that a Gaza pullout sets a dangerous precedent.

There are an estimated 8,200 settlers living among more than one million Palestinians in the Gaza Strip.