At least two people were killed and 20 injured on Saturday in a powerful blast that shook a six-storey residential building in the northern Lebanese city of Tripoli, a security official said.
It was not yet known what caused the explosion.
An official at Tripoli's Islamic Charity Hospital said 17 of those wounded were given first aid for light injuries and released, while three others were kept in for treatment.
Panicked residents, some still in their pajamas, were seen fleeing the area, which has been the scene of recent fierce sectarian clashes. One woman wept as she searched for her daughter.
The first floor of the building, with four apartments, was destroyed by the explosion along with several stores on the ground floor. Cars parked nearby were damaged.
Lebanese troops and police reinforcements were seen deploying in the area.
Violent confrontations erupted this week between Bab al-Tabbaneh and Jabal Mohsen. Nine people were killed and some 45 wounded in clashes between the two sides.
Two men were also wounded, one of them critically, when a grenade went off late on Friday. An army spokesman said one of the men had his leg torn off by the blast, which may have been accidental.
“Based on our initial investigation, the man who lost his leg was probably holding the grenade when it fell and exploded,” the spokesman told AFP.
The Tripoli clashes have raised fears of a nationwide security breakdown amid stalled efforts by Prime Minister Fouad Siniora to form a national unity government following a Qatari-brokered deal in May to end an 18-month political crisis.
The accord between the opposition and the ruling coalition led to the election of army commander Michel Sleiman as president, ending a six-month vacuum in the top job.
But the initial euphoria that greeted Sleiman's election has been replaced by a growing sense of foreboding, as rival factions continue to bicker over the distribution of key portfolios in the new 30-member government.
The Doha Agreement calls for the opposition to have veto power over key decisions in the unity cabinet and the drafting of a new electoral law ahead of legislative elections due next year.
The deal was struck after at least 65 people were killed in May in sectarian clashes that saw Hezbollah stage a spectacular takeover of mainly Sunni areas of West Beirut.
The violence sparked fears that Lebanon, which suffered a 15-year civil war that ended in 1990, was heading toward a new full-blown conflict.
-AFP/NOW Staff