Updated

The Gulf Cooperation Council has condemned the car bombing that ripped through a stronghold of Lebanon's Shiite movement Hezbollah in Beirut, killing at least 22 people.

"This criminal and disgraceful act is an attack on Lebanon's security and stability," GCC secretary general Abdullatif al-Zayani said in a statement late Friday.

Thursday's bombing at the heart of the densely populated Shiite southern suburbs of Beirut also targets "Lebanon's peaceful cohabitation, through sowing sedition" among its various confessions, he said.

The Gulf bloc, which groups Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates, imposed sanctions on Hezbollah in June over its military support for the Syrian regime against the mainly-Sunni rebels.

Zayani urged the Lebanese factions "not to give room to vandals, advocates of sedition and terrorists."

He said the GCC stands by Lebanon's side "against all that threatens its stability," offering condolences to the families of the dead.

A previously unknown group, the Battalion of Aisha, said it carried out the attack, which also wounded 325 people.

On Friday, Hezbollah leader Hassan Nasrallah blamed takfiris (radical Sunni Muslims) for the attack.

The blast came six weeks after a car bomb went off in a nearby neighbourhood and wounded more than 50 people.