Lebanon's state-run news agency says gunmen have exchanged fire in the country's largest Palestinian refugee camp, located near the southern port city of Sidon.
The National News Agency said Friday's clashes broke out in Ein el-Hilweh after the son of a former official with Palestinian President Mahmoud Abbas' Fatah group was shot dead.
Witnesses said a masked gunman killed Hussein Alaa-Eddine while he was participating in a protest against new Lebanese labor rules forcing Palestinians to get work permits to be able to work in Lebanon.
Ein el-Hilweh is notorious for its lawlessness and clashes are not uncommon in the camp, which the UN says is home to some 55,000 people.
It was established in 1948 to host Palestinians displaced by Israeli forces during the establishment of Israel.