Eight human rights activists and two trainers who were detained during a during a digital security and information management workshop organized by Amnesty International (AI) in İstanbul last week are at significant risk of torture, a U.N. human rights spokesman said on Friday.

According to Reuters, Elizabeth Throssell, spokeswoman for the U.N. High Commissioner for Human Rights, told a regular U.N. briefing in Geneva that she fears the detainees are at significant risk of torture and other cruel treatment.

“We are gravely concerned about all arbitrary arrests and detentions of human rights defenders in Turkey. We fear they are now at significant risk of torture and other cruel, inhuman or degrading treatment.”

The whereabouts of the detained human rights activists and two trainers have been determined, BBC Turkish reported on Thursday.

According to the report, the Helsinki Citizens Assembly said Özlem Dalkıran and Nalan Erken were at the Kartal Aslantepe Police Station; Veli Acu and Günan Kurşun at the Kartal Topselvi Police Station; Necat Taştan and Şeyhmus Özbekli at the Pendik Esenyalı Police Station; and AI Turkey director İdil Eser was taken to the Cumhuriyet Police Station in Istanbul’s Maltepe district.

The owner of the hotel, who was also detained with the activists, was released, while the two foreign trainers, a German and a Swedish national, were kept at a police station on Büyükada.

There is still no information as to what they are accused of and why they were taken to different police stations.

Speaking to the press after the G20 summit in Hamburg, Erdoğan signaled that the detention of the right defenders may turn into imprisonment, adding that their meeting was considered by security forces as a follow up to the July 15 coup bid.

“What was the reason for those [human rights defenders], who you just mentioned, to gather in a hotel in Büyükada (Princes’ Island)? They were there for a meeting [to plan something] that might be considered as a follow up to July 15 coup attempt. Police raided [the hotel] upon a tip from the intelligence agency. And they were detained as a result of that raid. They are not arrested yet. I don’t know the result of this detention process. It might trigger a trial process. It is a different matter. It is not at the hands of judiciary yet,” Erdoğan said.