At least 20 people were injured after clashes resumed between different Palestinian groups in a refugee camp in Lebanon, as the United Nations called for calm on Friday.
The violence erupted between fighters of the mainstream Fatah movement and other groups inside the Ain el-Hilweh camp late Thursday.
So far, 20 people have been reported wounded, the state-run National News Agency (NNA) said.
Witness said intermittent gunfire was still being heard on Friday afternoon, and that many residents had taken refuge in a nearby mosque.
Abu Ayad, a Palestinian official inside the camp, said Palestinian factions were working "on easing the situation."
The camp witnessed heavy clashes at the end of July following the assassination of Fatah commander Abu Ashraf al-Armouchi and several of his aides.
The fighting at that time resulted in the deaths of 13 people and the wounding of more than 35 others.
According to Palestinian sources, the clashes erupted late Thursday after fighters from some groups refused to evacuate eight of their posts inside the camp and hand over suspects linked to the killing of the Fatah commander.
Ain el-Hilweh is home to around 80,000 people. Most residents are Palestinian refugees from the first Arab-Israeli war in 1948 and their descendants.
Palestinians from Syria have also arrived because of the civil war in the neighboring country. There are some 12 camps hosting Palestinian refugees across Lebanon.
Meanwhile, the U.N. called on Palestinian groups to stop fighting in the Ain el-Hilweh refugee camp in southern Lebanon and to vacate United Nations Relief and Works Agency (UNRWA) schools immediately.
"I urge armed groups to stop the fighting in Ein al-Hilweh camp and vacate UNRWA schools immediately," said Imran Riza, the U.N. Resident Coordinator and Humanitarian Coordinator for Lebanon, in a statement posted on its official website.
Riza stressed in his appeal to the fighting groups that the ongoing clashes in the camp and the takeover of UNRWA schools in the camp "threaten children's right to education."
He added that armed groups' takeover of the eight UNRWA schools in the Ain el-Hilweh camp prevents "the access of nearly 6,000 children who are about to begin their school year."
Machine guns and heavy gun shells were used in Thursday's armed clashes in the refugee camp, forcing hundreds of refugees to flee the camp amid heavy fire, according to the Lebanese official news agency NNA.
Earlier on July 29, the camp saw heavy clashes between some groups and Palestinian forces affiliated with the Fatah movement, which left 11 people dead and more than 40 others injured, according to U.N. figures.
Established in 1948, Ain al-Hilweh is the largest Palestinian refugee camp in Lebanon, with 50,000 registered people, according to U.N. figures, though unofficial statistics put the camp's population at 70,000.
The total number of Palestinian refugees in Lebanon is estimated to be about 200,000, distributed among 12 camps, most of which are controlled by Palestinian factions.