DUBAI, United Arab Emirates >> Yemen’s Houthi rebels on Monday alleged a U.S. airstrike hit a prison holding African migrants, killing at least 68 people and wounding 47 others. The U.S. military said it was investigating.

The strike in Yemen’s Saada governorate, a stronghold for the Houthis, is the latest incident in the country’s decade-long war to see African migrants from Ethiopia and other nations killed while crossing the nation for a chance to work in neighboring Saudi Arabia.

It also likely will renew questions from activists about the American campaign, “Operation Rough Rider,” targeting the rebels as the Trump administration negotiates with their main benefactor, Iran, over Tehran’s rapidly advancing nuclear program.

The U.S. military’s Central Command, in a statement early Monday before news of the alleged strike broke, sought to defend its policy of offering no specific details of its extensive airstrike campaign. The strikes have drawn controversy in America over Defense Secretary Pete Hegseth’s use of the unclassified Signal messaging app to post sensitive details about the attacks.

“To preserve operational security, we have intentionally limited disclosing details of our ongoing or future operations,” Central Command said. “We are very deliberate in our operational approach, but will not reveal specifics about what we’ve done or what we will do.”

Late Monday night, the military said Central Command was “aware of the claims of civilian casualties related to the U.S. strikes in Yemen, and we take those claims very seriously.”

“We are currently conducting our battle-damage assessment and inquiry into those claims,” it added.

Graphic footage aired by the Houthis’ al-Masirah satellite news channel showed what appeared to be dead bodies and others wounded at the site. The Houthi-run Interior Ministry said some 115 migrants had been detained at the site.

The rebels’ Civil Defense organization said at least 68 people had been killed and 47 others wounded in the attack.

Footage from the site analyzed by the AP suggested some kind of explosion took place there, with its cement walls seemingly peppered by debris fragments and the wounds suffered by those there.

A voice can be heard repeating the start of a prayer in Arabic: “In the name of God.” An occasional gunshot rang out as medics sought to help those wounded.

The International Organization for Migration, a United Nations agency, said it was “deeply saddened” by the deaths at the prison.

“It is imperative that all efforts are made to avoid harm to civilians and to protect those most vulnerable in these challenging circumstances,” it said.

Ethiopians and other African migrants for years have landed in Yemen, braving the war-torn nation to try and reach Saudi Arabia for work. The Houthi rebels allegedly make tens of thousands of dollars a week smuggling migrants over the border.