Tripoli, Lebanon ? Lebanon’s army pounded Islamic militants hiding in a bombed-out Palestinian refugee camp Sunday for the third straight day, while fighting erupted outside another camp in the south, stoking fears of widespread violence breaking out in the country.

The Lebanese army shell a position being used by a militant sniper in the besieged Nahr el-Bared refugee camp Sunday near the city of Tripoli in Lebanon as the Lebanese army continued to battle against Islamic militants barricaded in the Palestinian refugee camp in northern Lebanon.

Fierce fighting has engulfed the outskirts of the Nahr el-Bared camp in northern Lebanon since Friday, when the Lebanese army – using tanks and artillery – launched an offensive to drive the Fatah Islam militants from their positions inside the settlement.

But they have faced strong resistance and the relentless bombardments threaten to anger Palestinians in the country’s other refugee camps, possibly causing violence to spread.

Near the southern city of Sidon, suspected members of the militant Islamic group Jund al-Sham fired a rocket-propelled-grenade at a Lebanese army checkpoint outside a camp Sunday, wounding at least five people, security officials said on customary condition of anonymity.

The attack prompted a shootout between the troops and militants, causing people to flee into homes and mosques for safety. It was not clear if the attack was related to the conflict in the north, but several hardline Islamic groups have called on Muslims to support Fatah Islam.

A senior Lebanese army officer said nine Lebanese troops have been killed in the fighting at the northern Nahr el-Bared camp since Friday, raising the army’s death toll to 44 since the standoff there began two weeks ago.

At least 20 civilians and about 60 militants have also been killed, but that doesn’t include casualties in the last three days because relief organizations and journalists have been prohibited from entering the camp.

Fatah Islam spokesman Abu Salim Taha told The Associated Press by phone that five militants, including a senior leader, had been killed and seven wounded since Friday.

The Lebanese government repeated its demand for the militants in Nahr el-Bared to surrender, but Fatah Islam’s deputy leader defied the call in a telephone interview with the AP.

“This is not only impossible, this is unthinkable. Our blood is cheaper than handing over our weapons and surrendering,” said Shehab al-Qaddour, who goes by the nom de guerre Abu Hureira.

He also denied the army had made significant progress in its offensive. He said militants had ambushed advancing forces Sunday, pushing them back a few yards on the north edge of the camp.

Security officials said the camp had been divided into three zones. The army and militants each controlled one zone, while Palestinian civilians and guerrillas controlled the third and were refusing the militants sanctuary. The officials spoke on condition of anonymity because they were not authorized to talk to the media.

The army claimed the militants had taken up positions in mosques and humanitarian centers inside the camp, using civilians as “human shields.” It was not clear how the military knew this, and it was impossible to independently confirm the claim. The militants have denied the accusation.