TRIPOLI, June 2nd  Lebanon – A missile-firing helicopter joined the Lebanese army offensive against al-Qaida-inspired militants on Saturday, the second day of a push against Islamic fighters vowing a fight to the death inside a Palestinian refugee camp. Army tanks shelled militant hideouts in the Nahr el-Bared camp by this northern port city, blasting upper floors of buildings where the militants placed snipers. A Lebanese air force helicopter fired two missiles and strafed militant positions in the first use of airpower since fighting began with the Fatah Islam group on May 20. The air attack was an apparent attempt to block an escape route to the Mediterranean Sea.Four soldiers were killed and 10 wounded Saturday in the offensive aimed at uprooting al-Qaida-inspired gunmen barricaded in the refugee camp.

The casualties raised the army’s deaths to 38 in two weeks. At least 20 civilians and about 60 militants were killed by Friday, but casualties in the camp in the last two days were unknown because relief organizations were banned from entering.Prime Minister Fuad Saniora said about 250 members of Fatah Islam were still inside the camp. He promised Palestinians who fled Nahr el-Bared that they will be able to return and the camp will be rebuilt. The militants "have no choice but to surrender," Saniora told Dubai-based Al-Arabiya television, adding that the government would "assure this group justice and a fair trial."There were signs that Palestinians trapped inside the camp were trying to squeeze the militants out.Abu Jaber, an official of the Popular Front for the Liberation of Palestine

Some Lebanese security officials consider the group to be a radical Sunni Muslim group tied to al-Qaida or inspired by al-Qaida’s militancy and doctrine. Saniora and others believe it is linked with Syrian military intelligence aimed at destabilizing Lebanon — a claim that Syria denied

Abu Jaber said 17 people had been wounded in the camp and about 400 houses destroyed in shelling Saturday.

"We hope that the army realizes that the shells are falling on the heads of innocent people," Jaber said by cellular phone from Nahr el-Bared.

Most of the camp’s 31,000 refugees fled to the nearby Beddawi camp earlier in the fighting, but at least 5,000 are believed still inside.

Official claim dozens of Fatah Islam militants were killed and wounded since Friday. But the group’s deputy commander, Abu Hureira, said only two fighters were wounded in the last two days.

He conceded that his fighters abandoned some positions on the camp’s northern edge in a "tactical" withdrawal, but denied the army had advanced.

"Let them come. We are ready," Abu Hureira told The Associated Press by cell phone, gunfire crackling in the background as he spoke. He denied reports that he and the group’s leader, Shaker Youssef al-Absi, were wounded.

An army officer, speaking on condition of anonymity because he was not allowed to talk to the media, said the troops will "continue advancing today and, hopefully, we will end it."

Conditions on the ground could not be verified. Journalists were pushed back from the camp and aid organizations were not allowed inside.

Lebanese security officials, speaking on condition of anonymity because they were not authorized to make statements to media, said Nahr el-Bared had been strategically divided into three zones. The army was controlling one zone, the militants held another, while Palestinian civilians and guerrillas controlled the third and were refusing the militants sanctuary, they said.

The army said the armed militants had taken up positions in the camp mosques and humanitarian centers, holding civilians as "human shields." It was not clear how the military knew this or how many Palestinians were used as human shields.