The United Arab Emirates is arbitrarily detaining 12 human rights activists who have already completed prison terms handed down over an alleged plot to overthrow the government, a U.N. document said on Friday. It called for their immediate release.

The document was released three weeks after relatives of the prisoners and rights activists said that more than 50 people sentenced for plotting to overthrow the UAE government were being held months and years after their jail terms had ended.

The dissidents are part of the so-called “UAE94” – a group of 94 lawyers, rights advocates and academics tried in 2013 and whose jail terms in the UAE began expiring in 2019.

The U.N. document said 12 dissidents whose multi-year sentences had all expired since July 2019 were being held due to their status as human rights defenders and because of their efforts “to hold the authorities to account”.

The UAE foreign ministry did not respond to Reuters requests for comment. UAE authorities have previously said allegations that prisoners were being held beyond the completion of their sentences were false and unsubstantiated.

The U.N. Working Group on Arbitrary Detention said the detentions violate several articles of the Universal Declaration of Human Rights.

“The appropriate remedy would be to release all the 12 individuals immediately and accord them an enforceable right to compensation and other reparations, in accordance with international law,” it said.

The document said the UAE did not respond to the opinion within the 60-day limit.

A list compiled by the Emirates Detainees Advocacy Center (EDAC) 51 people being held beyond their terms in the UAE, which in November will host the COP28 climate conference.