The Israeli army has confirmed its aircraft fired missiles into the southern Gaza Strip on Wednesday, where Palestinian infighting has consumed the region and killed at least 41 people in four days.

Israel launched the strike in spite of an earlier vow from the government that it would not play into Hamas's hands by allowing the faction to lure it into the increasingly violent Palestinian infighting.

"Israel is not going to be dragged into the Gaza Strip the way that Hamas wants. We will choose the time, the place to respond and we will protect our citizens," Israeli government spokeswoman Miri Eisin had said.

The Israeli army would not give any further details on its attack, but Palestinian security officials said an Israeli helicopter fired at least three missiles, while Hamas officials said the attack hit one of its security buildings and a car.

Reports said the Israeli air strikes killed at least five people and wounded dozens.

In the past two days, Hamas has fired more than 20 rockets into the southern Israeli town of Sderot.

The rocket attacks on Israel were an apparent attempt to draw Israel into the conflict so Palestinians could then unite against a common foe, CBC Middle East correspondent Peter Armstrong reported.

On Wednesday, gunmen in black ski masks roamed Gaza's near-empty streets as residents hunkered in their homes, which were left in the dark because of downed power lines. 

Journalists take cover

Violent outbursts erupted in many parts of the city. More than 30 international journalists from various media outlets took cover in the offices of Al-Jazeera television as heavy fighting erupted around them.

"We are, in fact, without exaggeration, in grave danger," said Al-Jazeera correspondent Wael Dahdouh, his words interrupted by sounds of gunfire.

Elsewhere, Hamas gunmen stormed the home of a Fatah security chief, killing six of his bodyguards, Palestinian security and medical officials said. The bodyguards were among at least a dozen guarding the home of Rashid Abu Shbak. Neither Abu Shbak nor his family were home.

In another incident, Hamas gunmen set fire to an 11-storey apartment building that is home to Nema Sheik Ali, a Fatah politician. The gunmen then stormed her apartment, she said.

"They came, they broke the door," she said. "They assaulted my children and they pushed me aside, then they torched the apartment."

Unresolved power struggle

Hamas also fired mortars overnight near the heavily guarded compound of Palestinian President Mahmoud Abbas of Fatah. The fighting did not reach the actual compound and Abbas was not present.

"What is happening in Gaza endangers not only the unity government, but the Palestinian social fabric, the Palestinian cause and the Palestinian strategy as a whole," said Palestinian negotiator Saeb Erekat.

The European Union issued a statement Wednesday calling on "leaders on all sides to renounce the use of violence immediately, to restore the cease-fire and to resume their dialogue."

The EU also denounced the Palestinian rocket fire at Israel.

This week's fighting was the worst since Hamas and Fatah agreed in February to share power. At the core of the fighting is the unresolved power struggle between Hamas, which won parliamentary elections last year, and Fatah, which dominated Palestinian politics for four decades.

The two sides never worked out all their differences, particularly over who would control Palestinian security forces.

Gaza's turmoil further weakened hopes for a resumption of Israeli-Palestinian peace talks, despite a new push by the Arab world to bring the sides to the table. The offer proposes Arab recognition of Israel in exchange for an Israeli withdrawal from all lands it occupied in the 1967 Mideast War.

However, negotiations would be impossible if the Palestinians descend into civil war.

With files from the Associated Press