GAZA CITY, 30 December 2005 — A Palestinian blew himself up yesterday, killing an Israeli Army officer and two other Palestinians at an Israeli checkpoint. The attack came as Palestinian police in Gaza searched for a British human rights worker and her parents, kidnapped at gunpoint in Rafah on Wednesday, and two feuding families filled the Gaza City air with gunfire. A policeman and one of the family members were killed.

The Palestinian bomber was in a taxi that was stopped at a roadblock near the West Bank town of Tulkarm for a security check. The army had set up a number of roadblocks in the area shortly after receiving warnings that a bomber was headed toward Israel.

Three occupants got out of the taxi, including a man wearing a large overcoat. When soldiers ordered him to remove it, he detonated an explosives belt concealed beneath it, the army said.

The army said the bomber, an accomplice and the taxi driver were killed, along with an Israeli Army officer, Lt. Uri Binamo, 21. Three soldiers were wounded, one seriously. Seven Palestinians were wounded in the blast, Palestinian doctors said.

Al-Arabiya satellite television said Islamic Jihad claimed responsibility, but this could not be confirmed.

Palestinians identified the attacker as Ala Al-Sadi, 23, a police officer from the northern West Bank town of Jenin. They said the family had links to Islamic Jihad.

Israel’s deputy defense minister, Zeev Boim, blamed local Islamic Jihad operatives for the attack.

Islamic Jihad has carried out all six bombings since Israel and the Palestinians declared a cease-fire last February. Israel has been targeting Islamic Jihad leaders in arrest raids in the West Bank and airstrikes in Gaza.

Palestinian official Saeb Erekat condemned the bombing and called on all groups to honor the cease-fire. “The Palestinian Authority is committed to the cessation of violence,” he said.

Israel shelled Gaza yesterday to enforce the new buffer zone designed to prevent activists from firing rockets from the Gaza Strip that Israeli troops quit three months ago after 38 years of occupation.

Optimism that the pullout would be a step to reviving talks on Palestinian statehood has shrunk, with both Israelis and Palestinians busy preparing for elections early next year that could reshape the landscape for peacemaking.

Israel said yesterday it would continue the shelling and airstrikes on Gaza for as long as it took to stop Palestinians from firing rockets.

Palestinians condemned the shelling. “The Israeli determination to implement this plan will widen the cycle of the conflict and will not achieve the goals which Israeli occupation forces seek to achieve,” the Palestinian Interior Ministry said in a statement.

Palestinian security forces yesterday hunted for a British human rights activist and her parents who were abducted in the Gaza Strip, but officials reported no immediate progress.

Kate Burton, a 25-year-old worker at the Palestinian rights group Al-Mezan, was showing her visiting parents around the chaotic southern border town of Rafah when they were kidnapped by gunmen on Wednesday afternoon.

Kamal Al-Sharafi, head of Al-Mezan, said: “Efforts to secure the release of the three were complicated because the kidnappers have neither identified themselves nor made any demands.”

Around seven kidnappers, armed with automatic rifles, intercepted a car the three Britons were traveling in, pulled them out and pushed them into a white vehicle that sped away.

Nothing has been heard from them or their kidnappers since and there has been no claim of responsibility.

Security forces set up roadblocks to search vehicles and car trunks on a road connecting Rafah to the rest of the Gaza Strip yesterday, 24 hours after the Britons were abducted.

Tawfiq Abu Khoussa, a spokesman for the Palestinian Ministry of Interior, said security forces would be on alert until the Britons were freed.

The Fatah Hawks, an armed wing of the mainstream Fatah movement vowed also to join the search and demanded that the kidnappers “free the hostages immediately,” calling the abduction “a criminal and cowardly action.”

The kidnapping was the latest in a string of abductions of foreigners in recent months. In most cases, the kidnappers sought jobs in the Palestinian security forces, release of imprisoned relatives or other personal matters. In all cases, the victims have been released unharmed.

— Additional input from agencies