At least 18 people were wounded by a car bomb blast in Beirut's southern suburbs on Tuesday, a stronghold of the Lebanese Shi'ite Hezbollah militant group that has been fighting in Syria's civil war, security sources said.
The sources were unable to confirm initial reports from medics at the scene that an unspecified number were killed in the massive blast.
Tensions in Lebanon have been high following the intervention of Hezbollah in support of President Bashar al-Assad's forces fighting a two-year revolt led by Syria's Sunni Muslim majority.
"This is the work of agents trying to create strife in Lebanon," said Hezbollah parliamentary Deputy Ali Meqdad at the site of the explosion.
A Reuters reporter on the scene saw a large fire raging at the site of the blast, which apparently targeted a shopping mall in the Bir al-Abed area. The area is also home to many Hezbollah political offices.
A pillar of dense black smoke billowed above surrounding high-rise apartment blocks. Ambulances and fire engines sped through the streets to rescue casualties.
Hezbollah gunmen cordoned off the area of the blast, which damaged cars and buildings. Fires were raging from dozens of cars which were set ablaze in the parking lot where the car rigged with explosives was left.
"I haven't heard an explosion like this one since the 1980s(when a car bomb targeted Hezbollah's late spiritual leader Sayyed Mohammed Hussein Fadlallah)," a woman in southern Beirut said.
Shopping areas would likely have been full on Tuesday, the day before the Islamic holy month of Ramadan begins.
The attack is the second strike to hit Shi'ite southern Beirut this year. Two rockets hit the area in May and Lebanese security forces have disarmed several rockets near Beirut in recent months as well.