JERUSALEM, July 5 — At least 11 Palestinian militants were killed in airstrikes and armed clashes during an Israeli Army incursion into central Gaza on Thursday, Palestinian medical officials said. It was one of the bloodiest days for Hamas since it took control of the Gaza Strip three weeks ago.

Hamas officials said that seven of the dead were members of its military wing, known as the Qassam Brigades, mostly men in their early 20s. The Islamic Jihad faction said one of its men was among the dead. The affiliation of the other three was not clear.

Israeli military officials described the raid as a routine operation to root out “terrorist infrastructures” and search for weapons and wanted men. Israel’s Army Radio reported that dozens of Palestinians suspected of involvement in terrorism were being questioned in Gaza.

But Hamas officials accused Israel of trying to provoke an escalation of the conflict after a few days of relative quiet on the Gaza-Israel border. A Hamas spokesman, Sami Abu Zuhri, said the incursion was “an Israeli plan to end the resistance and to shake the government, despite its successes and achievements.”

He was referring to the deposed Hamas-led government of Ismail Haniya, which was fired by the Palestinian president, Mahmoud Abbas, of the rival Fatah faction, after Hamas’s violent conquest of Gaza. Mr. Abbas appointed an emergency government to operate from the West Bank, but the Hamas leadership holds sway in Gaza and is trying to prove that it can impose order there.

The Israeli forces entered Gaza early Thursday, penetrating about half a mile into Palestinian territory, an Israeli Army spokesman said. Palestinian officials said the fighting was focused in areas east of two refugee camps, Maghazi and Bureij.

Two squads of armed Palestinians were hit from the air as they were spotted approaching the ground forces, and five more armed Palestinians were hit in exchanges of fire on the ground, the army spokesman said. Two Israeli soldiers were lightly wounded when a rocket-propelled grenade was fired at an army bulldozer, the spokesman said.

Dr. Muawiya Hassanein, director of the emergency medical service in Gaza, said 25 Palestinians had been wounded.

One of the wounded Palestinians was a cameraman for the Hamas-affiliated Al Aksa satellite television station who was filming the clashes. Al Jazeera television showed videotape of the cameraman lying wounded on the ground, then being shot twice in the legs from afar. The Palestinian cameraman who filmed the shooting said the fire had come from the direction of the Israeli forces.

The army spokesman, who had seen the videotape on Al Jazeera, said the army was looking into what had happened, but added that it was hard to determine from the pictures who had shot the cameraman.

“It was a battle zone,” he said.

Al Aksa has been the only local television station broadcasting in Gaza since Hamas took over and closed the official pro-Fatah Palestinian Authority broadcasting company.

An Israeli military official speaking on condition of anonymity under army rules said that Aksa cameramen should not be considered bona fide journalists, but “Hamas operatives in every respect.” He said that they gathered intelligence, documented Hamas attacks on Israeli forces, joined squads of armed men and were sometimes armed themselves.

Maj. Avital Leibovich, an army spokeswoman, said Aksa television was “no ordinary media outlet.”

“Its cameramen are part of the organization, and go out with them on missions,” she said. “That has to be taken into account.”

Israel withdrew its troops from Gaza and evacuated all Jewish settlements there almost two years ago. The latest ground incursions occurred after a sharp escalation of hostilities between Gaza militants and Israel in May. Then, the Hamas military wing and other Palestinian factions fired about 300 rockets toward Israel, and Israel carried out dozens of airstrikes, mainly against Hamas security operations and rocket-launching cells.

Hamas has ceased firing rockets for now, and fires only mortar shells and rocket-propelled grenades, Mr. Abu Zuhri said. He said that the militants who confronted the Israeli tanks and soldiers on Thursday were protecting the border areas.

Sporadic rocket fire still comes from Gaza. An Israeli Army spokeswoman said the last time a rocket was fired before Thursday’s incursion was on Tuesday evening. She said that two more rockets were launched Thursday afternoon during the army operation.

Also on Thursday, the separate Palestinian governments in the West Bank and Gaza had a battle of wills over the Palestinian weekend. Government workers have always taken off Thursday and Friday, but this week, Salam Fayyad, who leads the emergency cabinet in the West Bank, decreed that the official weekend was changing to Friday and Saturday.

In Gaza, hundreds of Palestinian Authority employees headed to work at 8 a.m. on Thursday, intending to follow the orders of the West Bank government, which pays their salaries. Hamas dispatched forces to prevent the workers from reaching their jobs.

Muhammad Bkair, 30, a Housing Ministry employee, said five members of the Executive Force, the Hamas police militia, were blocking the entrance to his workplace. He said he and a crowd of other workers waited 30 minutes, then three jeeps arrived with reinforcements.

“They kept shooting in the air and referred to us as sheep,” Mr. Bkair said. “They referred to one employee as a collaborator. We were obliged to leave.” But, he added, “On Saturday we will not come.”

Taghreed El-Khodary contributed reporting from Gaza.

Copyright 2007 The New York Times Company