Israeli troops killed a top leader of the violent Islamic Jihad in a West Bank raid Saturday, the group said, and the Israelis also pressed ahead with their offensive in the Gaza Strip.

In announcements from mosque loudspeakers, Islamic Jihad said the leader of its militant wing in Nablus, Hani Awijan, 29, was killed by Israeli undercover troops. They came to arrest him while he was playing soccer with friends and relatives, the group said. Another Islamic Jihad militant was also killed.

The army confirmed soldiers operated in Nablus and said a militant was killed in an exchange of fire.

Israel Radio said Awijan was responsible for a series of attacks on Israelis. Over the past 17 months, Islamic Jihad has been responsible for all 12 suicide bombing attacks in Israel, killing 71 people.

News of the raid spread through Nablus, and large crowds gathered at the hospital. Militants burned tires in the streets and called for a general strike in the city. Shops were quickly closed.

While most attention is on the Israel-Lebanon conflict and the monthlong Israeli offensive in Gaza, Israeli forces carry out nightly arrest raids in the West Bank, searching for suspected militants. Often more than 20 are detained in a single night.

Israel moved tanks and troops into Gaza and started an intensive campaign of airstrikes after Hamas-linked militants tunneled under the border and attacked an Israeli army post at a crossing point, killing two soldiers and capturing a third.

Palestinian officials said they have not received a response to their demand that Israel guarantee that it will free women, children and long-serving Palestinian prisoners before an Israeli soldier seized by Gaza militants is released.

Dr. Salah Bardawil, a senior Hamas official, said Israel's refusal to guarantee that it would release any Palestinian prisoners if the soldier were freed had created a stalemate.

Early Saturday, some Israeli tanks moved back into Gaza a day after completing a two-day raid in the northern part of the seaside strip in which 30 Palestinians were killed. Most were armed militants, but some were civilians, including an elderly woman and a child.

Late Saturday, residents reported Israeli tanks moving in a buffer zone east of Gaza City, a frequent area of Israeli operations to try to stop Palestinian militants from firing rockets at Israeli communities.

In airstrikes early Sunday, Israeli aircraft destroyed a house belonging to a militant in Gaza City, residents said. Israel warned the occupants to leave, and the house was empty. Other targets were the house of a militant leader in the town of Beit Hanoun and a shop in Gaza City where neighbors said a well-known criminal sold weapons. Nine people were wounded in the attacks, four seriously, hospital officials said.

Also, Israeli aircraft fired missiles near the southern town or Rafah, knocking out electricity. The Israelis said they were aiming at a site where Palestinians were tunneling under the Gaza-Egypt border.

Since Israel pulled out of Gaza last summer, turning control of the border over to Egypt and the Palestinians, the Israeli military has said that cross-border smuggling of weapons and explosives has increased considerably.