Some Syrian opposition groups have adopted methods of abuse similar to those employed by the government of President Bashar al-Assad, Amnesty International has said that document a “chilling” wave of torture, abductions and summary killings in insurgent-controlled areas.

The report is based on interviews with some 70 individuals living or working in the northern provinces of Idlib and parts of Aleppo, areas controlled by insurgents.

The abuses were committed over four years by five armed groups, including some backed by the US and other regional powers, and al-Qaida’s branch in Syria, Amnesty said.

“While some civilians in areas controlled by armed opposition groups may at first have welcomed an escape from brutal Syrian government rule, hopes that these armed groups would respect rights have faded as they have increasingly taken the law into their own hands and committed serious abuses,” said Philip Luther, director of Amnesty’s Middle East programme.