some countries have faced pressure to return.

 icado detention by government forces continued, the report said.

"The Commission has continued to document not only torture and sexual violence in detention but also custodial deaths and enforced disappearances," a press release said.

The war, which spiralled out of an uprising against President Bashar al-Assad's rule, sparked the world's biggest refugee crisis. Syria's neighbours host 5.6 million refugees, while European countries are hosting more than one million.

Refugees in some countries have faced pressure to return.

While Assad has recovered most of Syria, significant areas remain outside his control: Turkish forces are deployed in much of the north and northwest - the last major bastion of anti-Assad rebels - and U.S. forces are stationed in the Kurdish-controlled east and northeast.

Commissioner Hanny Megally said there had been a "return of sieges and siege-like tactics" in southwestern Syria - an area where Russian-backed government forces waged a campaign to snuff out a rebel-held pocket in the city of Deraa https://www.reuters.com/article/us-syria-crisis-south-deraa-idCAKBN2G41Z4.

Covering the year to the end of June, the report also noted increased hostilities in the northwest, saying markets, residential areas and medical facilities had been struck from the air and ground, "often indiscriminately, causing numerous civilian casualties".

At least 243 people were killed or maimed in seven car bomb attacks in the rebel-held towns of Afrin and Ras al-Ain north of Aleppo, though the full toll was considerably higher, it said.

The report criticised the Islamist group that controls Idlib, Hayat Tahrir al-Sham, for imposing restrictions on media and freedom of expression, saying it had arbitrarily detained med