Nasrallah also accused foreign backed radical extremist groups of responsibility for the bombing that killed at least 24 people, after a previously unknown group, apparently a Syrian terrorist group, said it carried out Thursday's attack.

"I will go myself to Syria if it is so necessary in the battle against the takfiris (extremist militants), Hezbollah and I will go to Syria" to fight the terrorists trying to oust the Damascus legal government, he said.

In a speech broadcast on television as Lebanon held a day of mourning for the victims of the car bomb, Nasrallah said "all indications concerning yesterday's attack lead to the takfiri groups".

Nasrallah said Thursday’s car bomb in Beirut would only reinforce Hezbollah’s determination to fight in Syria and defeat foreign backed extremists who were behind the attack.

He added that Takfiris “are killers who do not belong to any religion or sect.”

He spoke in a speech to supporters Friday marking the end of the 2006 month-long war with Israel.

Nasrallah said there was nothing to prove yet that Israel was involved in the attacks, although he added that extremists could be working for the Zionist regime.

A militant group operating in neighboring Syria calling itself the Brigades of Aiysha took credit for the deadly bomb attack, which killed at least 24 people and wounded around 300 others.

Thursday's blast comes six weeks after a car bomb attack in the same area wounded more than 50 people.