Amnesty International on Thursday condemned the "horrific violations" being committed against migrants returned to Libya with the cooperation of European states after trying to cross the Mediterranean.

It said new evidence had emerged of "harrowing violations, including sexual violence, against men, women and children" intercepted at sea and forcibly returned to detention centres in the north African country.

The rights group, in a report, condemned "the ongoing complicity of European states" for cooperating with the authorities in violence-strewn Libya.

At the end of 2020, Libya's Directorate for Combatting Illegal Migration had "legitimised" abuses by taking over two detention centres run by militias from where hundreds of refugees and migrants had forcibly disappeared, it said.

It cited survivor testimony from one facility of guards subjecting women to sexual violence "in exchange for their release or for essentials such as clean water".

Amnesty urged Europe to "suspend cooperation on migration and border control with Libya".

Italy and the European Union have for years financed, trained and provided aid to the coastguards to stop smugglers from taking migrants and refugees in flimsy boats across the Mediterranean to Europe.

Despite being plunged into chaos after the fall of Moamer Kadhafi's regime in 2011, Libya has become a favoured springboard for migrants seeking a better life in Europe.

UN agencies and nongovernment organisations operating in the Mediterranean regularly denounce European policies of forced return of migrants.

'Hellscape of detention' 

Diana Eltahawy, Amnesty's deputy director for the Middle East and North Africa, called the rights group's new report "horrifying".

It "sheds new light on the suffering of people intercepted at sea and returned to Libya, where they are immediately funnelled into arbitrary detention and systematically subjected to torture, sexual violence, forced labour and other exploitation with total impunity", she said.

European nations "have shamefully continued to enable and assist Libyan coastguards in capturing people at sea and forcibly returning them to the hellscape of detention in Libya, despite knowing full well the horrors they will endure", Eltahawy said.

Eltahawy said Libya's detention network was "rotten to its core and must be dismantled".

Since the start of the summer, the number of crossings has increased as migrants take advantage of good weather, but the number of people lost at sea has also risen.

Nearly 900 migrants have died this year trying to reach Europe from North Africa, according to the International Organisation for Migration.

The UNHCR said Libya's coastguard returned more than 13,000 people to Libya between January and June this year, surpassing the number returned in the whole of 2020.