GENEVA (AP) — The United Nations migration agency said Thursday it was “deeply concerned” about some 260 Somali and Ethiopian migrants allegedly held and mistreated by criminal gangs in Libya, saying it believed that a harrowing video of them posted on social media was authentic.

The International Organization for Migration noted the video posted June 9 on Facebook in which it said many “abused Somalis and Ethiopians are seen huddled fearfully in a concrete room.”

The IOM said a Somali journalist based in Turkey recorded the video call from a gang in which some migrants claimed to have been beaten. Some alleged having their teeth pulled out and arms broken.

The authenticity of the video could not be independently verified.

The agency said some captives’ relatives had received videos asking them to pay $8,000 to $10,000 “or their child or relative will be killed.” The relatives’ exact location was not known, but the IOM said “the relevant authorities in this situation have been informed.”

Libya has been without a stable, central government since the fall of Moammar Gadhafi in 2011.