At least 15 people have died in Aleppo, Syria, after a twin barrel bombing blasted a wake for victims of a similar attack days earlier.

Regime aircraft dropped two explosive-packed barrels minutes apart on a rebel-held enclave in the east of the city, according to the British-based Syrian Observatory for Human Rights.

Dozens more were injured in Saturday's strikes, said the group, near a tent where mourners were paying respects to 11 children and four others killed in a barrel bomb attack on Thursday.

Image: The death toll is expected to grow from the latest attack

Sky News Foreign Affairs Editor Sam Kiley, who is in Gaziantep, just across the border in Turkey, said this kind of assault is known as the "double tap" in Aleppo.

Luring rescue workers to scenes of carnage caused by barrel bombs and then dropping a second on them, he says, has become a standard trick of the Assad regime and its Russian allies.


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Aleppo - once Syria's economic powerhouse - has been split between rebels in the east and government control in the west for most of the civil war, which broke out in March 2011.

The Syrian government denies using barrel bombs, but reporters and activists on the ground say the regime and its Russian ally are the only ones operating helicopters over Aleppo.

Also on Saturday, Syrian state TV reported that the siege of Daraya, a Damascus suburb, was declared over after four years, as insurgents and civilians were evacuated.

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Image: Rebel fighters and their families are seen on buses after evacuating Daraya

Under the deal, some 700 gunmen were allowed to leave with their families to the northern rebel-controlled Idlib province.

The agreement followed a government siege of Daraya, which was the last bastion against President Bashar al Assad in Syria's western Ghouta region.

State TV said on Saturday that Daraya was clear of gunmen, and under the control of the Syrian army.