Amnesty International last week published a report calling for investigations into a network of unofficial prisons across southern Yemen where it said "egregious violations" have been committed, including enforced disappearances and torture.

The UAE has dismissed the report as politically motivated and said it does not manage or run any prisons in the war-torn country.

General Joe Votel, who heads the US Central Command that oversees US operations in the Middle East, said he had spoken to Emirati counterparts on the issue.

"I am satisfied that the appropriate investigations are underway to determine the facts associated with this," Votel told Pentagon reporters.

"We have the confidence that (the Emiratis) will continue to operate in a manner that befits their values and ours."

The United Arab Emirates has played a key role in a Saudi-led -- and US-backed -- military intervention since 2015 to bolster Yemen's President Abedrabbo Mansour Hadi against Iran-backed Huthi rebels.

Both loyalist and rebel forces stand accused of failing to protect civilians in a war that has killed nearly 10,000 people, 2,200 of them children, and pushed the country to the brink of famine.

Amnesty International said it had investigated 51 cases of enforced disappearance at the hands of UAE-backed forces between March 2016 and May 2018.

Nineteen of the men remain missing, it said.