Interior Minister Ahmed al-Maysari made the demand in a meeting with the UAE’s minister of international cooperation.

Yemeni Interior Minister Ahmed al-Maysari has demanded that informal prisons run by the United Arab Emirates in the war-torn country be closed, the official SABA news agency said on Wednesday.

Al-Maysari, who made the demand during talks held in Aden on Monday with Reem al-Hashemi, the UAE’s minister for international cooperation, expressed concern in the past over the UAE’s oversight of the prisons.

This, however, is the first time that al-Maysari brought up the issue with a senior Emirati official. The meeting was also attended by the top UAE military commander in Yemen, Brigadier Gen Mohammed al-Hassani.

An investigation by the Associated Press earlier in June found that hundreds of Yemeni men were swept up into a network of prisons under the suspicion of being al-Qaeda or ISIL fighters. The news agency said the prisoners were being held without charges or trial.

According to the AP report, Yemeni guards working under the direction of Emirati officers used various methods of sexual torture and humiliation.

The guards allegedly raped detainees while others filmed the assault, electrocuted prisoners’ genitals or hung rocks from their testicles.

The UAE’s state minister for foreign affairs dismissed on Sunday reports that his country controls prison or set up a base on the Yemeni island of Socotra as fake news.

“In Yemen, the Emiratis have been subjected to an unjust smear campaign because it bears its responsibility toward regional security with courage and boldness,” Anwar Gargash said.

In Yemen’s three-year civil war, UAE forces that are purportedly fighting on behalf of Yemen’s government have taken over wide swaths of territory in the south.

In late 2014, Iran-backed Houthi rebels took over much of northern Yemen, including the capital Sanaa, and forced out the government of Abd-Rabbu Mansour Hadi.

The following March, direct international involvement in the conflict began, spearheaded by Saudi Arabia and the UAE who remain active in Yemen today, executing a relentless air campaign in support of the Hadi government.