Rights group Amnesty International has condemned what it called the complicity of European states in horrific abuses suffered by migrants intercepted at sea and forcibly returned to Libya.

A report by the group suggests that conditions in Libyan detention centres are worsening and migrants are subjected to torture, forced labour, sexual violence, and extortion.

Amnesty urged European countries to suspend cooperation on migration and border control with Libya.

United Nations figures say the Libyan coastguard returned more than 13,000 people to Libya in the first six months of this year.