The fighting marked a new escalation in the army's battle with Islamic militants, as the fighting shifted from the bomb-ravaged, besieged Palestinian refugee camp of Nahr el-Bared on Tripoli's outskirts back to the city itself, where violence first erupted May 20.

A soldier, a policeman and two family members were killed in Sunday's confrontation, the security officials said, speaking on condition of anonymity because they were not authorized to speak to the media. They said six of the gunmen were also killed — three Saudis, an ethnic Chechen and two Lebanese who also held European citizenships.

According to the officials, at least two of the militants had been living there for some time. Others took refuge there with them on Saturday.

The slain policeman lived in the besieged, two-building complex. The gunmen first tried to take his family hostage, then killed him, his daughter and his uncle, the security officials said.

Fayez Sayyed, a 43-year-old grocery store owner who lived in a fourth-floor apartment, said his wife briefly encountered the gunmen. "Two bearded men knocked on the door and asked her to open, but she didn't," Sayyed said.

Before Sunday's gun battle, Tripoli had not seen fighting since the first week of the conflict with Fatah Islam militants at Nahr el-Bared, Lebanon's worst internal violence since the 1975-90 civil war.

Lebanese Defense Minister Elias Murr declared victory over the militants Thursday, and the army said the next day it had overrun Fatah Islam's main positions inside the camp.