Smoke billows from damaged buildings hit by a Lebanese army artillery shell, during a fighting with Islamic militants, at the Palestinian refugee camp of Nahr el-Bared, in the northern city of Tripoli, Lebanon, Friday July 13, 2007. Islamic militants fired back volleys of rockets at the Lebanese army on Friday as troops pounded the remaining suspected hideouts of the Fatah Islam fighters holed up in a Palestinian refugee camp in north Lebanon. [AP]

Regular artillery and tank fire fell on Nahr el-Bared, sending plumes of black smoke rising in the air over the refugee camp's bullet-punctured buildings.

Apparently trying to ease the military pressure and expand the battles outside the camp, the al-Qaida-styled militants unleashed a volley of Katyusha rockets at the army.

A total of nine rockets crashed into nearby villages, as well as in orange and grape groves, security officials and the state-run National News Agency said. The rockets caused some damage but no casualties, said the officials, speaking on condition of anonymity because they were not authorized to talk to the media.

"It has more a psychological effect than a military effect," said Elias Hanna, a retired Lebanese army general.

Fatah Islam gunmen also traded heavy fire with the troops circling them in the refugee camp, soldiers said.

"They shot back with rocket-propelled grenades and machine-guns," said a soldier sitting in a military jeep a few hundreds meters from the camp. He spoke on condition of anonymity because he was not authorized to talk to the media.

The army had reported four soldiers died in the previous day's fighting, but a senior military official raised the death toll to six on Friday.

The six soldiers, including an officer, were killed by shrapnel or gunfire during the fierce fighting Thursday when the army unleashed one of its heaviest bombardments against the Fatah Islam militants, said a military official, speaking on condition of anonymity because he was not authorized to make statements.

The deaths brought to 92 the number of soldiers killed since fighting began on May 20.

An amateur tape obtained by The Associated Press Television on Friday showed masked Fatah Islam gunmen hiding in a building damaged by artillery fire in Nahr el-Bared.

"Enemies of God," shouted a gunman, apparently referring to Lebanese soldiers before the din of gunfire echoed in the distance.

The tape then showed the body of a dead man wrapped with a blanket, while two wounded men were brought to a clinic inside the camp. Medics, flanked by a veiled woman and other relatives of the wounded, were seen struggling to save the two wounded. A rescuer breathed air into the mouth of one of the two wounded.

The tape showed damaged or bullet-punctured cars in the camp's deserted streets littered with debris. Two veiled women and two unarmed men scurried for cover.

The army buildup came after a sniper inside Nahr el-Bared killed a soldier late Tuesday night, and following repeated refusals by the Fatah Islam group to surrender.

Lebanese officials claimed victory June 21 after troops seized Fatah Islam positions on the camp's edges, but the militants retreated deeper into the warren of densely packed buildings and firefights have continued daily.

At least 60 militants and more than 20 civilians ¡ª including a man who died Thursday after being hit by a stray bulled ¡ª have been killed in the fighting, the country's worst internal violence since the 1975-90 civil war. The camp housed more than 30,000 Palestinian refugees before the battles began.

Most of the camp's residents have already fled, but a few thousand are thought to have stayed in their homes.