Lebanon: Deadly car bomb rocks Beirut, killing at least 22 (VIDEO)

UN Secretary-General Ban Ki-moon on Thursday condemned a deadly car bomb attack in southern Beirut that left at least 22 people dead and another 300 wounded. 

Ban said the latest violence was "completely unacceptable" and urged Lebanese people to remain united in the face of "severe regional turbulence." 

The explosion happened in the capital city's Rweiss district, a stronghold of the militant group Hezbollah.

A previously uknown Islamist group, likely linked with the Syrian rebels, claimed responsibility for the attack in a video posted online.

The Sunni Islamist group "Brigades of Aisha" warned Hezbollah leader Sayyed Hassan Nasrallah that: "This is the second time that we decide the place of the battle and its timing … And you will see more, God willing," reported Reuters. 

Lebanese TV showed dozens of ambulances and firefighters streaming to the site of the blast, where several buildings had reportedly caught fire, said the AP. The casualty count was not immediately clear, with differing numbers from Reuters, the BBC and the Associated Press. By Thursday that number had jumped to 22.

This is indeed the second car bomb attack in Beirut in little over a month; the last incident, in July, also targeted the Abed area, according to Lebanon's Daily Star.

Tensions have been mounting in Lebanon due to the war raging in nearby Syria, in which Hezbollah is believed involved, and many fear there could be a spillover in violence. 

The AP said some Syrian groups have also threatened to take revenge on Hezbollah over Syria, where violence has taken an estimated 100,000 lives. 

Here's footage of the blast, as carried by CNN: