Two people were killed and four wounded on Saturday when a verbal argument turned violent in the Palestinian refugee camp of Ain el-Helweh in south Lebanon, a Palestinian official said.
Those killed were Walid Sallum, a member of a committee formed to resolve differences between rival Palestinian factions, and Abed Jawali, a member of the Islamist group Jund al-Sham, the official said.
They were hit by bullets fired during an altercation between Shehade Jawhar, a Jund al-Sham leader, and members of a joint force of Palestinian factions which polices the camp, said the official.
Jawhar was seriously wounded, the official said, speaking on condition of anonymity. He could not say who fired the shots.
After the clash, two rocket-propelled grenades were fired and sporadic gunfire broke out in the camp, in which three Palestinian civilians were wounded.
The factional force tasked with security is dominated by the Palestine Liberation Organization, of which Palestinian president Mahmoud Abbas's Fatah movement is a principal member.
Ain el-Helweh, near the southern port city of Sidon, with more than 45,000 inhabitants, is the largest Palestinian camp in Lebanon.
In recent months it has become the theatre of clashes between Fatah and Jund al-Sham, a Sunni group comprising mainly Lebanese without a clear hierarchy.
Members of extremist groups believed to have links with Al-Qaeda have settled in Lebanon's Palestinian refugee camps in recent years, especially in Ain el-Helweh.
The camps are outside the control of Lebanese authorities, with Palestinian factions in charge of security.