The alleged beatings began as soon as the Venezuelans arrived in El Salvador, Yamarte Fernandez said. The men, who were in handcuffs and chains, were immediately removed from the plane and taken to CECOT, where they say they were kicked, beaten and shaved.

Venezuela says it is opening a formal investigation into several Salvadoran officials, including President Nayib Bukele, over the alleged abuse of Venezuelan migrants deported from the US.

Some of the Venezuelans detained in El Salvador's notorious Cecot prison have alleged physical assault, sexual abuse and torture.