GAZA CITY, Gaza Strip -- Israeli forces backed by 30 tanks and three helicopters stormed into central Gaza City early Thursday -- the deepest incursion into the city in more than two years, Palestinian security officials and witnesses said.

In the second major incursion by Israeli troops in as many days, the army raided the two-story home of Yosef Meqdiad, an officer in the Palestinian preventive security service, to arrest him and three of his brothers, according to a 21-year-old relative, Majida Meqdiad.

The operation began about 2 a.m. and ended less than two hours later. Soldiers fired machine guns as they penetrated just over a mile into the city from the south, witnesses said.

The army declined immediate comment.

The incursion marked the farthest penetration by Israeli forces into the city since renewed fighting erupted between Palestinians and Israelis in the fall of 2000, witnesses said.

It came hours after Yasser Arafat warned Wednesday against any attempt to send him into exile, while Israeli Cabinet ministers repeated calls to drive the Palestinian leader out of the region following an attack that killed five Israelis.

The proposal to expel Arafat, backed by several members of Israel's Security Cabinet, failed to win approval Wednesday.

Nablus incursion

The move into Gaza City also followed Wednesday's incursion into the West Bank's largest city, Nablus, by dozens of Israeli tanks and armored vehicles to round up 30 suspected Palestinian militants in what was the biggest security sweep in months.

In Thursday's early-morning raid in central Gaza City, Israeli forces rolled into the Talalhawa neighborhood, an area where the headquarters of the preventive security service and the studios of Palestinian state television are located.

Troops also swept into the neighborhood of Sabra, home to many members of the militant Palestinian group Hamas, including its spiritual leader, Sheik Ahmed Yassin.

Two Palestinians were taken to the hospital with light injuries.

The Israeli invasion of Nablus was triggered by a Sunday shooting at an Israeli communal farm in which five people, including two small boys, were killed by a gunman from the Al Aqsa Martyrs' Brigade, a militia linked to Arafat's Fatah group. The attacker managed to flee the scene.

Israeli officials identified the gunman as Sirhan Sirhan, a 19-year-old from the Tulkarem refugee camp. Officials initially said they believed he was a distant relative of the assassin by the same name who killed presidential candidate Robert Kennedy in 1968 -- but later withdrew that claim.

Israeli security officials have said the order for the communal farm attack came from militiamen in Nablus.

Arafat denounced the Nablus raid as a "new war crime."

Prime Minister Ariel Sharon said in a television interview Wednesday that Israel's security chiefs have advised him not to expel Arafat, as demanded by several hard-line ministers in his Cabinet. But he also said the debate would continue.

Sharon's comments came after Foreign Minister Benjamin Netanyahu urged for the second time in two days that Arafat be expelled. Sharon has sought to diminish Arafat's powers and the government has halted direct dealings with the Palestinian leader.

In a speech Tuesday night, Netanyahu said if he becomes prime minister in January elections, his first move would be to expel Arafat.

He renewed the call at Wednesday's Security Cabinet meeting, and was supported by Defense Minister Shaul Mofaz, according to Netanyahu's spokeswoman, Rena Riger.

Arafat responded angrily to Netanyahu.

"Netanyahu has to remember that I am Yasser Arafat and that this is my land and the land of my grand-grand-grand-grand-grandfathers," he said on the steps of his offices in the West Bank town of Ramallah, just north of Jerusalem.

Arafat has spent almost all of the past year at his headquarters and has stopped traveling abroad. Israel has said he is free to go, but suggested he may not be allowed to return to the Palestinian territories.