You can guarantee it was either Al Nusra Front or the Islamic State of Iraq and the Levant.

BEIRUT, Aug 15 (Reuters) – A powerful explosion struck the southern Beirut stronghold of Lebanon’s militant Hezbollah group on Thursday, killing 10 people, wounding 120 and trapping many others inside damaged buildings, witnesses and emergency officials said.

The blast, a month after a car bomb wounded more than 50 people in the same district of the Lebanese capital, came amid sectarian tensions over the intervention of Shi’ite Muslim Hezbollah against Sunni rebels in Syria’s civil war.

Residents of southern Beirut say Hezbollah, backed by Iran and Syria, was on high alert and stepped up security in the area after warnings from Syria rebels of possible retaliation for the group’s support for President Bashar al-Assad.

It was not immediately known whether the explosion targeted any Hezbollah figure but it took place in a crowded residential area.

“I don’t know what happened. It’s as if we were struck by an earthquake,” one young man at the scene told Reuters, bleeding from a wound to his stomach.

A spokesman for Lebanon’s Red Cross said 10 people were killed and another 120 were wounded.

At the heart of the site, where fires still raged almost an hour after the blast, the twisted remains of a large van could be seen and some witnesses said they believed the explosion was caused by a car bomb.

Many cars were damaged in the explosion and the blast sent a column of black smoke over the densely populated area. The facades of several residential buildings were damaged. Charred bodies were seen inside cars caught in the explosion.