Venezuela has announced an investigation into claims migrants sent to a prison in El Salvador from the US suffered human rights abuses.

More than 250 Venezuelans were repatriated to near Caracas on Friday. They had been detained in El Salvador since March following their deportation from the United States.

Venezuelan Attorney-General Tarek William Saab said there had been “systemic torture” inside the prison, which included sexual abuse, daily beatings and rotten prison food.

El Salvador is yet to respond to the claims.

During a press conference, Saab presented testimonies and images appearing to show detainees with injuries including bruising and missing teeth. These claims have not been independently verified by the BBC.

Venezuela will investigate El Salvador’s President Nayib Bukele, Justice Minister Gustavo Villatoro and Head of Prisons Osiris Luna Meza.

The attorney general urged the International Criminal Court (ICC), the UN Human Rights Council and relevant bodies in the Americas to “do the same”.

Venezuela is currently facing an investigation by the ICC in The Hague for allegations similar to those the country is levelling at El Salvador, including torturing prisoners and denying them access to legal representation.

The Venezuelans were deported in March under the 1798 Alien Enemies Act, which gives a US president power to detain and deport natives or citizens of “enemy” nations without usual processes. They were accused of belonging to a gang, something many of the men’s relatives and lawyers deny.

They were held in the notorious Terrorism Confinement Center, known as Cecot, which was originally built to hold accused gang members.

Read: El Salvador’s secretive mega-jail

The group did not have access to lawyers or their relatives, and were last seen in photos issued by Bukele’s government which pictured them arriving in handcuffs with their heads shaved, which sparked international outcry.

They were released in mid-July by El Salvador in exchange for US nationals held in Venezuela, with a senior Trump administration official telling reporters that they extended their “deep,deep gratitude” to Bukele for facilitating the deal.

The US has imposed heavy sanctions on Venezuela, and in May the Supreme Court ruled that the Temporary Protected Status for Venezuelan nationals could be revoked, affecting about 350,000 people.