At least two people have been killed and several others, including three soldiers, wounded in separate clashes at Palestinian refugee camps in Lebanon, officials said.
Monday's violence started at the Nahr al-Bared camp near the costal city of Tripoli after the funeral of a refugee who had been killed by the military on Friday, according to a security official.
"One Palestinian refugee was killed and seven others were wounded by gunfire," the official said on condition of anonymity.
The Lebanese army said in a statement that three soldiers were injured in the clashes.
The army used "tear gas and rubber bullets, and then fired live rounds at people who insisted on attacking (a military post), leading to several of the attackers being injured," said the statement.
It added that youths threw Molotov cocktails at the soldiers and torched an army vehicle as well as part of the military post. It blamed "infiltrators" for the unrest.
A camp resident said soldiers had opened fire on the youths without provocation.
"The situation in the camp has been tense for days," another camp resident told AFP news agency.
"Both the army and the youths were provoking each other. We fear something bigger is being prepared, because the army is deploying in large numbers around the camp now."
On Friday, the army shot dead a Palestinian and wounded three others when a dispute over identity papers at Nahr al-Bared turned violent, a Palestinian source said.
News about Monday's clashes quickly spread to other Palestinian camps across the country, including Ain al-Helweh, the largest Palestinian refugee camp in Lebanon, located on the outskirts of the southern port of Sidon.
Local media reported at least one resident of the camp was killed in clashes with the army.
Residents burned tyres, threw stones and opened fire near an army checkpoint at the northern entrance to the camp, an AFP correspondent said.
The army opened fire to disperse the crowd. Six people - three Palestinians and three Lebanese - were also injured, a security source said.
Protests were also said to be held at Beddawi refugee camp near Tripoli, and Shatila refugee camp in the capital Beirut.
Nahr al-Bared was almost totally destroyed in 2007 during a months-long conflict between the Lebanese military and a small al-Qaeda-inspired group called Fatah al-Islam.
The fighting killed some 400 people, including 168 soldiers.
The military controls access to the camp and has checkpoints inside Nahr al-Bared - the only one of 12 Palestinian refugee camps in Lebanon under the direct control of the Lebanese security forces.
By long-standing convention, the Lebanese army does not enter the camps, leaving security inside to the Palestinians themselves.
The United Nations Relief and Works Agency for Palestinian refugees (UNRWA) estimates that some 425,000 Palestinian refugees are living in Lebanon, a country with a population of four million.
Others, however, estimate the number to be closer to 250,000.