Syrian warplanes hammered Damascus on Monday with loud explosions shaking the capital on the fourth day of a Muslim holiday marked by the failure of a ceasefire bid, an AFP correspondent said.

The explosions, which appeared to come from several different districts, could be heard over about two hours and were among the most intense in the city since the beginning of the 19-month conflict.

The Arab League ambassador to France said Sunday that world powers have to agree on a "minimum accord" on Syria for there to be any chance of resolving the crisis in the conflict-hit country.

"If we don't manage to create a minimum accord between the powers, the friends of the (Syrian government and opposition), we can never start a transitional political process," Nassif Hitti told French media TV5 Monde, RFI and Le Monde.

A home-made weapons manufacturer in north Lebanon was killed in a blast in his workshop on Sunday while trying to make a machinegun for Syrian rebels, a Lebanese security official told Agence France Presse.

Marwan al-Qassab was working on a DShK heavy machinegun to be smuggled into Syria to support the insurgents when a blast rocked his workshop, the official said on condition of anonymity.

Residents of the Akkar plain town of Tal Andeh on Sunday blocked the international highway linking northern Lebanon to Syria in protest at the Syrian authorities' arrest of town resident Samer Ahmed al-Nuaim, Lebanon's National News Agency reported.

The protesters erected a tent in the middle of the street, stressing that they will not remove it before the release of Nuaim.

Syrian Islamist group al-Nusra Front has denied responsibility for a bombing in Damascus that dramatically shattered a ceasefire, instead blaming the regime, SITE Intelligence Group reported on Sunday.

Friday's car bomb explosion struck a residential area housing police officers and their families, killing at least eight people and wounding more than 30, on the first day of an attempted ceasefire for the Muslim holiday of Eid al-Adha.

Abducted Lebanese journalist Fidaa Itani has reassured that he was in good health in a YouTube video uploaded on Sunday.

In the video uploaded by his abductors, a Syrian rebel group calling itself the Aazaz Northern Storm Brigade, Itani said he was in good health, clarifying that he is “under house arrest.”

Enraged Syrian pilgrims on Sunday cursed President Bashar Assad and prayed for his death as they hurled pebbles at pillars representing Satan in the final ritual of the annual hajj pilgrimage.

Rebel flags billowed among vast crowds of Muslim pilgrims who heaved towards the stoning site in the Saudi holy city of Mina amid the chanting of anti-Assad slogans.

Iraq stopped and searched a Syria-bound cargo plane from Iran for weapons for the second time in a month on Sunday, but allowed it to continue as no banned items were found, an official said.

The United States has been pressuring Baghdad to ensure all Iranian aircraft flying through its airspace are ordered to land and checked for weapons, but Iraq has said it will only stop planes when it has doubts about the cargo being transported.

Fighting, air raids and a car bombing shook Syria on Sunday, monitors said, as the international community looked to pick up the pieces of a failed bid to halt the violence for a Muslim holiday ceasefire.

Rebels stormed regime positions in the suburbs of Damascus as air strikes pummeled opposition-held areas on the outskirts of the capital, activists and a watchdog said.

The Syrian army on Saturday accused rebels of committing increasing violations of a failed truce proposed for the Muslim Eid al-Adha holiday and vowed to fight back.

"For the second day, terrorist groups continued to flagrantly violate the ceasefire announced and respected by the army command," the military said in a statement on state television.