Israeli soldiers shot dead seven Palestinian Arabs in clashes, and an airstrike destroyed two rocket launchers after southern Israel was hit by unguided Kassams for the first time since Hamas took over the Gaza Strip.

The gun battles in the West Bank and Gaza, the rocket attacks, and the airstrike marked the first extensive Israeli-Palestinian Arab fighting since the Islamic Hamas’s violent takeover of Gaza last week. The Palestinian Authority president, Mahmoud Abbas, who is the leader of the Fatah movement, retains control of the West Bank along with an emergency government that he named this week.

Five Palestinian Arab militants died in fighting in central Gaza near Israel’s Kissufim crossing, doctors at Nasser Hospital in the Gaza town of Khan Yunis, said in telephone interviews. Hamas said in a leaflet that its gunmen, who accounted for three of those killed, fought the soldiers with grenades.

The clashes in Gaza began after Israeli forces crossed the border fence in an operation aimed at clearing out Palestinian Arab fighters and destroying weapons-smuggling tunnels and other infrastructure, an Israel Defense Forces spokesman, speaking anonymously, said in a telephone interview. The forces penetrated a few hundred meters into Gaza, he said.

The Israeli airstrike on northern Gaza destroyed two rocket launchers in an open field and didn’t cause injury, a Palestinian Arab security official said on condition of anonymity. An Israeli army spokeswoman said the strike came after Palestinian Arabs fired rockets at southern Israel.

Palestinian Arab militants have fired more than 300 Kassams at Israel since mid-May, although the barrage briefly stopped after Hamas wrested control of Gaza.

In the West Bank, Israeli soldiers on an arrest raid encountered heavy fire during which they killed two armed Palestinian Arabs, the army spokesman said.

Mr. Abbas dismissed Prime Minister Haniyeh’s cabinet last week, a move that Mr. Haniyeh and his Hamas movement rejected, leaving two competing governments in the Palestinian Authority.

Prime Minister Olmert of Israel and President Bush pledged support yesterday for Mr. Abbas’s government and said they would pursue efforts to revive peace talks. America and the European Union, which consider Hamas a terrorist organization, have said they would resume aid to Mr. Abbas’s government while continuing sanctions on Hamas.

Dozens of civilians fleeing Hamas have been waiting near the Palestinian side of the Erez crossing in the northern Gaza Strip to travel through Israel to the West Bank. Yesterday, Israeli tanks moved there after Palestinian Arab gunmen attacked Erez, killing one of the civilians.

The Israeli defense minister, Ehud Barak, yesterday instructed the army to allow “urgent humanitarian cases” waiting on the Palestinian side of the crossing to enter Israel for medical treatment, his office said in a statement read over the telephone by a spokeswoman.