Unknown assailants tossed overnight a hand grenade in the Palestinian refugee camp of Ain el-Helweh in the southern city of Sidon, reported the National News Agency on Tuesday.
It said that no one was injured in the attack.
The assailants threw the grenade in the al-Fawqani street in the camp.
The joint Palestinian security forces unit retaliated to the incident by firing gunshots in the air.
Ain el-Hilweh frequently witnesses clashes between its various armed factions.
By long-standing convention, the Lebanese army does not enter the Palestinian camps in the country, leaving the Palestinian factions themselves to handle security.
That has created lawless areas in many camps, and Ain el-Helweh has gained notoriety as a refuge for extremists and fugitives.
