The death toll from a car bombing that ripped through a Beirut stronghold of the Lebanese Shiite movement Hezbollah has risen to at least 27, the health ministry said Saturday.
The toll is the highest in Lebanon since a massive car bomb attack on the Beirut seafront killed then prime minister Rafiq Hariri and 22 others in February 2005.
"At least 27 people died and 336 others were wounded in the car bomb attack that targeted the Rweiss neighbourhood on Thursday," the office of Health Minister Ali Hassan Khalil said.
An earlier toll on Friday said at least 22 people had been killed when an explosives packed car blew up in the densely populated mostly-Shiite district in Beirut's southern suburbs.
But Khalil's office said three people died of their injuries overnight Friday while two more bodies were found, raising the death toll.
A previously unknown group, the Battalion of Aisha, said it carried out the attack because of Hezbollah's involvement in the Syria war.
"You, the pig Hassan Nasrallah, we send you our second powerful message because you haven't understood yet," a member of the group said referring to the head of Hezbollah.
Hezbollah is a key supporter of President Bashar al-Assad and has sent fighters across the border to Syria this year to bolster government forces, which have been battling a deadly anti-regime revolt since March 2011.
A defiant Nasrallah said on Friday he himself was ready to go and fight in Syria, and accused radical Sunni takfiri Muslims of being responsible for the car bombing.
Lebanon is deeply divided into supporters and opponents of the regime in neighbouring Syria and the conflict now in its third year has stoked sectarian tensions and violence in the country.
Also on Saturday, the Syrian opposition National Coalition warned against a "cycle of violence" in Lebanon if Hezbollah continues to send fighters to help the Damascus regime.
"We have repeatedly warned the head of Hezbollah against siding with the Assad regime in killing Syrian people but he continues to be involved in the regime's crimes," said the group.
"This situation if it continues will push Lebanon into a cycle of violence that will serve Israeli interests," it added in a statement.