CAIRO (AP) — An international rights group is calling for an investigation into alleged disappearances, torture and likely deaths in prisons run by the United Arab Emirates and allied militias in southern Yemen, as possible war crimes.

Amnesty International says it has documented "systemic enforced disappearance and torture and other ill-treatment, amounting to war crimes" in the facilities.

Thursday's report says "some (detainees are) feared to have died in custody."

The UAE is part of a Saudi-led coalition battling Iran-backed Shiite Houthi rebels in Yemen since March 2015.

The Associated Press reported last year that the UAE and its allied militias were running a network of secret detention facilities, beyond the control of Yemeni government. In June, the AP revealed that hundreds of detainees had been subjected to sexual abuse and torture.