Ramallah, April 3 (Reuters): Palestinian President Yasser Arafat said today he was unmoved by a threat by Israeli Prime Minister Ariel Sharon to assassinate him which had drawn criticism from the US.

Arafat was speaking to reporters at his battered headquarters in Ramallah hours after a Palestinian gunman infiltrated a Jewish settlement in the West Bank, killing a settler and wounding his 12-year-old daughter before soldiers shot the attacker dead.

In interviews with Israeli newspapers yesterday, Sharon had issued his most explicit threat yet against Arafat, calling the Palestinian leader a poor insurance risk. “I don’t care for it. I am caring for my people, for our children, for our women, for our students,” Arafat, speaking in English, said in his first response to Sharon’s remarks.

The US criticised Sharon’s comments, but Israel’s internal security minister Tsahi Hanegbi defended the Prime Minister’s remarks today and noted that US forces had killed militants in Iraq and Afghanistan.

The Hamas militant group claimed responsibility for the attack on the West Bank settlement. In telephone calls to Reuters, it said it was done “to avenge the assassination” on March 22 of the group’s leader, Sheikh Ahmed Yassin, by an Israeli helicopter strike in Gaza.

Hamas has waged a decade-old campaign of attacks against Israelis, including suicide bombings that have killed hundreds.

Israeli soldiers later launched arrest sweeps in two West Bank towns, and took 23 Palestinian suspects into custody in Nablus, a military source and witnesses said.

In the Gaza Strip, two Israeli helicopters opened fire with machineguns at the crowded Rafah refugee camp, apparently during a chase after militants, witnesses said. There were no immediate reports of injuries.

An Israeli military source confirmed the shooting but said the troops aimed at open spaces and not at any homes.