They said a military official of Palestinian President Yasir Arafat's faction was among those killed in an ambush near one of the group's offices in the Ain al-Hilwa camp near the southern port city of Sidon.
A second member of the group was also killed in the
fighting, as was a 14-year-old girl hit by a stray bullet that
smashed into a hospital several hundred metres from the
fringes of the camp, hospital officials said.
Fatah armed men fanned out in the streets after the shooting, the latest outbreak of violence in the camp, where friction
between competing Palestinian factions has often flared into battle with small arms and grenades.
Lebanese forces do not enter the camp, one of a dozen in the country where some 350,000 Palestinians are registered as refugees.
Lebanese authorities point to the camps as a haven for militants and organised crime.