Updated

A Palestinian gunman opened fire in a Jewish settlement in the Gaza Strip on Wednesday, killing two Israelis and wounding one before being shot dead, the army said.

The Islamic militant group Hamas claimed responsibility for the attack on the Shalev settlement. It identified the gunman as Ismail Braiss, 25.

The attacker infiltrated the area of the settlement's greenhouses, apparently with a group of Palestinian laborers, and opened fire on Israelis working there, security sources and Israeli Radio said.

Tnaged to reach the area of the greenhouses and fired a little and I killed him," the settlement's security chief, Kobi Haddad, told Israel Radio.

The shooting came hours after Israeli police arrested five Arab men suspected of terrorist activity near Tel Aviv's Ben Gurion Airport. Police would not say if the five suspects were Palestinians or Israeli Arabs or if they were armed.

It was not immediately clear if the group was planning to attack the international airport, but the overnight police sweep shut down main highways, while police set up roadblocks and patrols throughout central Israel.

The violence came a day after Israeli Prime Minister Ariel Sharon announced an early election, throwing the country into three months of political instability as it prepares for a Jan. 28 poll.

Avi Pazner, a government spokesman, said security forces had received at least 60 warnings about planned Palestinian bombing and shooting attacks.

"In spite of the fact that we have elections in Israel, we are able to continue our struggle against terrorism, without relenting and with all the necessary means which we have, and the Palestinians are making a big mistake if they believe they can shake our resolve," Pazner said.

In the West Bank town of Jenin, Israeli troops conducted house-to-house searches in a downtown neighborhood, arresting all men age 15 or older, Palestinian witnesses and security officials said.

In the Balata refugee camp near Nablus, soldiers arrested seven neighbors of a homicide bomber who blew up in the Israeli town of Kfar Saba on Monday, killing two Israelis.