BEIRUT - A Syrian branch of al-Qaida on Tuesday claimed responsibility for what the group said were suicide attacks on security compounds in Damascus that killed at least five people, while troops fought rebels on the edge of the capital in the latest surge of violence in the Syrian capital.
The claim by Jabhat al-Nusra - the first in months - came as the U.N.'s special representative trying to end Syria's civil war said hopes for convening a peace conference next month are fading.
The Nusra Front has emerged as the most effective fighting force on the side of the opposition fighting to oust President Bashar Assad. The group has previously claimed car bombings and attacks on government soldiers and its fighters have been leading other rebels groups in battles for military bases in the north much of which is under control of the opposition.
The group's affiliation with al-Qaida, however, has significantly contributed to the reluctance of the opposition's Western backers to arm the rebels with heavier weapons.
More than 93,000 people have been killed since the Syrian conflict began in March 2011. It started as peaceful protests against Assad's rule but turned into a civil war after some opposition members took up arms to fight the government's harsh crackdown on dissent. Since then, radical groups like the Nusra front have gained influence on the battlefield as opposition's political leadership struggles to unify its ranks.
The conflict has taken increasingly sectarian tones with Sunni Muslims dominating rebel groups fighting against Assad's regime, which is predominantly Alawite, an offshoot sect of Shiite Islam.
Even the most modest international efforts to end the Syrian conflict have failed.
In Switzerland, U.N.'s special envoy to Syria, Lakhdar Brahimi, told reporters he still hopes a second round of international negotiations to find a political solution to the conflict can be convened in Geneva - but not until later in the summer.
"Frankly now, I doubt whether the conference will take place in July," he said, noting that the Syrian opposition is not meeting until early July and probably would not be ready.
"Since our previous meeting here on the 5th of June, the situation on the ground in Syria has hardly improved. It is still relentless destruction, killing, more suffering, more injustice, and more uncertainty for the future of the Syrian people," Brahimi said.
Brahimi was mediating a meeting between the U.S. and Russia, which are at loggerheads over the conflict.
Russia supports the regime and Washington has backed the opposition, which insists Assad should relinquish power before any talks with Damascus can take place. Assad has repeatedly dismissed demands to leave power and said he has the right to run for another term in next year's presidential elections.
Jabhat al-Nusra claimed responsibility for Sunday's attacks in Damascus in a statement posted on a militant website, warning Assad that his "criminal regime" should know that its fighters "do not fear any confrontation with the enemies."
The group said it had sent seven suicide bombers wearing Syrian military uniforms to break into a police station in northern Damascus and a security compound in a southern district of the capital. The group also posted several pictures claiming to show the attackers. Their faces blurred, the men are seen wearing military uniforms and holding Kalashnikovs as they sit on the ground with Jabhat al-Nusra black banner hanged behind them.
"The criminal and traitor regime should know that Sunni people stand on solid ground and brave men who do not fear any confrontation with the enemies...and they are ready to sacrifice their blood in order to protect the souls and honor of their people," the statement said.