Lebanon’s Prime Minister Tammam Salam (3rd R) speaks during a legislative session at the parliament building in downtown Beirut, Lebanon Novemver 12, 2015. Lebanon’s parliament convened on Thursday for its first legislative session in more than a year as lawmakers prepared to vote on mostly financial issues vital to keeping the paralyzed state afloat. REUTERS/Mohamed Azakir

By John Davison

BEIRUT (Reuters) – Lebanese Prime Minister Tammam Salam held an emergency meeting with his security cabinet and military chiefs on Friday as the nation mourned 44 people killed in a double suicide bombing claimed by Islamic State.

The blasts late on Thursday hit a residential and commercial area in a southern suburb of Beirut, a stronghold of Shi’ite Muslim group Hezbollah, in the latest spillover of violence from the war in neighboring Syria.

The first attacks in more than a year on a Hezbollah bastion inside Lebanon came at time when the group is stepping up its involvement in Syria’s civil war, now in its fifth year.

Iran-backed Hezbollah has sent troops over the border to support Syrian President Bashar al-Assad against Sunni Muslim insurgent groups including Islamic State.

Lebanon is also suffering from its own political crisis in which disputes between parties, factions and sects have stopped the government taking basic decisions and left the country without a president for 17 months.

The army established a heavy security presence around the scene of the blast, which on Friday morning was still littered with debris, damaged cars and motorbikes and shattered glass.

Medical sources raised the death toll on Friday from 43 to 44, with more than 200 people wounded.

Justice Minister Ashraf Rifi said after the security meeting there was "complete trust" in Lebanon’s security forces to maintain relative calm in the country, which suffered its own civil war from 1975 to 1990.

POLITICAL PARALYSIS

Rifi urged politicians to put all rivalries aside and work towards electing a president and bolstering the government and parliament. State institutions are paralyzed by political deadlock.

Beirut residents expressed concern after the violence, saying it raised the specter of civil strife.

"It’s been a year… with no explosions. We thought we were done with this, but were proved wrong yesterday," said central Beirut resident Rajaa, who gave only her first name.

"This explosion targeted Lebanon as whole, not only Beirut’s southern suburbs," she said.

Mahmoud Hammoud, speaking near the scene of Thursday’s attacks, was resolute: "Every time we have another martyr, our nation becomes stronger," he said.

The pro-Hezbollah al-Akhbar newspaper said there was "no room for retreat", after the powerful Shi’ite militant movement warned of a "long war" against its enemies.

U.N. Secretary General Ban Ki-moon urged Lebanon’s security services and state institutions "not to allow this despicable act to destroy the relative calm that has prevailed in the country over the past year."

The White House pledged to support the country as it worked to "bring those responsible for this attack to justice".

Hezbollah’s political opponents in Lebanon also condemned the attacks. Sunni politician Saad al-Hariri, who leads the Future Movement, said the they were "cowardly… and unjustified" in postings on his Twitter account.

Syria’s civil war is increasingly playing out as a proxy battle between regional rivals, including Iran and Saudi Arabia which support opposing sides in the conflict. The two adversaries also back opposing political forces in Lebanon.

Lawmakers were to convene in Beirut for a second day on Friday in the first legislative session for more than a year. The meeting aims to pass urgent financial laws to keep the state afloat, but is avoiding thorny political issues.

(Additional reporting by Issam Abdallah, Ahmad Kurdi, Walid Saleh and Hassan Abdallah; Editing by Mark Heinrich)