BEIRUT (Reuters) - Rebels in Syria with ties to al Qaeda have decapitated a man believed to have been a pro-government Shi’ite fighter, an amateur video of the public beheading posted to the Internet on Saturday showed.

The Syrian Observatory for Human Rights, a monitoring group which posted the video, said the beheading was conducted by the Islamic State in Iraq and the Levant (ISIL), a foreign-led group fighting to overthrow President Bashar al-Assad and establish an Islamic emirate in Syria.

The footage shows armed men in black standing outdoors in a circle around a man who is lying on the grass. One of the militants leans over the victim and appears to cut off his head with a small knife, cheered on by the others.

Once the head is detached, the militant holds it up and places it on the man’s back before it rolls off and settles on the ground about a meter (3 ft) away from his body.

The remainder of the three-minute video shows the crowd, which includes several children, talking, laughing and taking photographs of the scene.

The Britain-based Observatory, which opposes Assad and has an extensive network of sources across Syria, said the video was taken in the central province of Homs. Its authenticity could not be independently verified.

Hard-line Islamist rebels with links to al Qaeda have come to dominate the largely Sunni Muslim insurgency against Assad, who is supported by members of his minority Alawite sect - an offshoot of Shi’ite Islam - as well as Shi’ite fighters from Iraq and Lebanon’s Hezbollah.

Both sides in Syria’s nearly three-year conflict have been implicated in torture, killings and other war crimes.

The rise of al Qaeda in Syria has forced some in the West to temper calls for Assad’s removal from power. The Syrian government cited atrocities like the beheading at the ‘Geneva 2’ peace conference in Switzerland last week in an attempt to characterize all of its armed opponents as “terrorists.”

The first round of talks ended on Friday without any progress towards ending the civil war, which has killed more than 130,000 people, displaced nearly 6 million others and aggravated sectarian tensions across the region.

FIGHTING CONTINUES

On the first day since talks recessed in Geneva, the Syrian government pressed on with its assault of rebel-held areas across the country, the Observatory said.

Aerial bombardment in Aleppo’s eastern district of Tariq al-Bab killed at least 33 civilians, including two women and six children, it said.

Clashes also flared between ISIL and rival rebel factions seeking to push the group out of rebel-held swathes of northern and eastern Syria.

Twenty-six militants from both sides were killed in fighting that erupted after two car bombs hit an infantry school in Aleppo which one of the rebel groups was using as its headquarters, according to the Observatory.

Further south in Hama province, ISIL killed a rival rebel leader and six other fighters in an ambush.

Shelling and an attack by unknown assailants on a supply line in Homs caused residents to lose electricity across Homs province, as well as the eastern province of Deir al-Zor, according to the Observatory.

In Damascus, the Syrian Arab Red Crescent managed to evacuate hundreds of sick and malnourished civilians from the Yarmouk district, which government forces have besieged for months. (ID:nL5N0L60IR)

Syria’s conflict began in March 2011 with popular protests against Assad, but evolved into a civil war after a crackdown by security forces led to an armed uprising.