Army troops are making "significant" gains in their long-running battle against Al Qaeda-inspired fighters barricaded inside a Palestinian refugee camp in northern Lebanon, security officials said Tuesday.

But a senior military official, who spoke on condition of anonymity because he is not authorized to speak to the media, said four soldiers were killed in fighting Monday. The body of a missing soldier also has been found, he said.

The latest deaths raise to 103 the army's death toll since the fighting broke out nearly two months ago.

The security officials, who also spoke on condition of anonymity, reported "significant progress" by the troops, saying militants from the Fatah Islam group were now encircled in an area no bigger than 500 square meters.

They did not elaborate.

An Associated Press photographer standing a few hundreds meters from the camp said the army was using armored bulldozers to push its way through the rubble in the devastated camp. Three armored personnel carriers could also be seen parked atop the rubble of destroyed buildings, he said. The army placed a security camera on the collapsed rooftop of one of the buildings, he added.

But gunfire and the impact of rocket-propelled grenades could still be heard from inside the camp Tuesday, suggesting that the militants continued to resist the army's advance.

Lebanon's state-run National News Agency said a Katyusha rocket was fired from inside the camp Tuesday, landing in a village about three miles away. There were no reports of casualties.

An army statement issued late Monday said troops captured two militants while pursuing the fighters in the camp's old neighborhoods.

Some local and Arab television stations on Tuesday spoke of unconfirmed reports that the body of Abu Hureira, the deputy Fatah Islam leader whose real name is Shehab al-Qaddour, was found among those of other fighters in the camp.

But the reports could not be immediately verified.

The conflict with Fatah Islam militants, which erupted May 20, is Lebanon's worst internal violence since the 1975-90 civil war. At least 60 militants and more than 20 civilians have been killed in the fighting, according to the Lebanese government and U.N. relief officials.