BEIRUT: The Free Syrian Army Friday condemned and rejected responsibility for the execution of regime loyalists in the northern city of Aleppo after a video emerged of the reported killings.

“We strongly condemn this kind of irresponsible behavior and call on all revolutionary forces and the fighters on the ground to condemn such acts,” the FSA’s joint command statement said.

The rebel leadership insisted the killings were “unacceptable, isolated and illegal” and that the FSA had no links to those who carried them out.

“These reprehensible acts do not conform with the ethics of the FSA or the Syrian revolution.

“We respect international laws and conventions, notably the Geneva Convention on the treatment of prisoners,” it said and called for an investigation.

Amnesty International Friday said an investigation by the FSA “into the alleged unlawful killings of 14 members of the Barri clan […] should be referred to the U.N. Commission of Inquiry on Syria.

“Killing captives is a serious violation of international humanitarian law and a war crime. The FSA leadership have a duty to end such violations immediately,” Philip Luther Amnesty’s Middle East and North Africa head said.

Amateur video posted on YouTube by activists apparently showed FSA fighters executing regime loyalists from the Al-Barri tribe Tuesday in Aleppo, which the two sides have been battling for control of since July 20.

The gunmen chanted “The FSA forever!” as they led members of the tribe into a square.

One of the captives had been stripped almost naked, as rebels stood him against a wall. Other captives were lined up next to him, as the rebels chanted “Allahu akbar” (God is greatest).

They opened fire on their captives, identified as members of a tribe fighting Tuesday in Aleppo on the side of the regime. The Barri clan is Sunni Muslim while the Assad regime is dominated by Alawites, an offshoot of Shiite Islam.

Amnesty warned Wednesday about disturbing reports of “summary executions” by both Syrian troops and rebels, calling them “serious violations of international law.”