Deadly blast hits Hezbollah neighborhood

A car-bomb explosion tore through a Hezbollah-controlled neighborhood in the southern suburbs of Beirut on Thursday, killing at least 22 people according to the Health Ministry. It was the bloodiest attack yet on Lebanese civilians that has been linked to the ongoing Syrian civil war.

At least 290 people were injured in the blast, which occurred between the Bir el-Abed and Roueiss neighbourhoods -- an area regarded as the heart of the Shiite militant group's territory in Beirut.

The public space is used by Hezbollah to hold neighborhood residents and supporters whenever Hassan Nasrallah, the group's head, delivers a speech.

The blast set buildings and cars on fire and sent a column of black smoke over the densely populated area.

The attack raises the specter of a sharply divided Lebanon being pulled further into the conflict next door, where Hezbollah has become increasingly and more openly involved in recent months.

A little-known Syrian Sunni group called Aisha Umm al Mouemeneen claimed responsibility for the bombing and threatened further attacks against Hezbollah.

Al Jazeera's Zeina Khodr, reporting from Beirut, said Hezbollah has been receiving threats from some groups linked to the Syrian opposition.

"We know Hezbollah lost a lot of popularity after it sent its fighters into Syria to support the Syrian regime against the opposition," she said.

As a result of the bombing, caretaker Prime Minister Najib Mikati declared Friday a national day of mourning, and called on the Higher Defense Council to hold meetings.

Several residents were trapped inside six burning buildings following the explosion, according to the Red Cross.

Hezbollah's Al Manar television channel said several bodies were seen on the street following the explosion.

Television footage showed cars on fire and several injured people. The blast sent a column of black smoke over the densely populated area.

Last month a car bomb exploded in another southern Beirut suburb, wounding more than 50 people.

Al Jazeera and wire services