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.

Regular artillery and tank fire could be seen falling 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 Qaeda-styled militants unleashed a volley of Katyusha rockets at the army on Friday.

A total of nine rockets crashed into villages neighboring the refugee camp, 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.

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 yards 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 the official, speaking on condition of anonymity because he was not authorized to make statements.

Thursday's fatalities brought to 92 the number of soldiers killed since fighting erupted on May 20.

A Lebanese man, identified as Adel al-Ajel, also died Thursday in a hospital after being hit in the head by a stray bullet on a highway near Nahr el-Bared, the state-run National News Agency reported.

An armored personnel carrier was seen Thursday ferrying at least two injured soldiers out of the camp, but the total number of wounded was not known, the military official said.

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.

The army denied in a statement Thursday it was conducting its final assault against the militants barricaded inside the camp.

"The ongoing military operations are still in the context of tightening the noose on the gunmen to force them to surrender," the statement said.

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

At least 60 militants and more than 20 civilians have been reported 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 already have fled, but a few thousand are thought to have stayed in their homes.