A car bomb struck a northeastern Lebanese town close to the Syrian border during rush hour on Thursday, killing at least three people and wounding more than 20, security officials said.
It was the latest in a wave of attacks to hit Lebanon in recent months as the civil war in Syria increasingly spills over into its smaller neighbor, attacks that have killed scores of people here and bitterly divided the Lebanese.
The bomb went off in the center of the predominantly Shiite town of Hermel, which is about 10 miles from the Syrian border and a stronghold of Lebanon's militant Hezbollah group.
The officials said the explosion took place near two banks and close to the town's main government where people go to get official documents. One of the dead was removed from a car near the blast and ambulances were rushing others to hospitals, the officials said, speaking on condition of anonymity in line with regulations.
There were three others bodies, including one that officials believe might have been the suicide attacker.
Lebanon's state-run National News Agency quoted Health Minister Ali Hassan Khalil as saying that the blast killed four and wounded 26.
Photos posted by local TV stations showed thick black smoke billowing from the center of the town while others showed mangled cars.
President Michel Suleiman denounced the attack and called on the country's security forces "to intensify efforts to detain instigators and criminals and bring them to justice."
Hermel's mayor, Sobhi Saqr, told Hezbollah's Al-Manar TV that the attack occurred as students were on their way to schools and while employees were going to work.
"It was a very big blast," Saqr said.
The violence in Lebanon has targeted both Sunni and Shiite neighborhoods, further stoking sectarian tensions that are already running high as each community in the country lines up behind its brethren in Syria on opposing sides of the war.
In the past months, Syrian opposition fighters have fired rockets from Syria into Hermel, killing and wounding a number of people. The rebels said their attacks were in retaliation for Hezbollah's involvement in Syria's civil war on the side of President Bashar Assad's forces.
The blast came a day after Lebanese troops captured a senior operative with an Al Qaeda-linked group that has carried out attacks across the Middle East.
Jamal Daftardar of the Abdullah Azzam Brigades was detained during a raid in an eastern Lebanese village near the Syrian border.
Wednesday's capture came a day after the Abdullah Azzam Brigades vowed to target Iran and Hezbollah following the death of its leader in Lebanon. The leader, Majid al-Majid, was arrested by the Lebanese army last month and authorities said he later died at a military hospital in Beirut from a chronic illness.