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 decadelong 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, known as “Operation Rough Rider,” which has been targeting the rebels as the Trump administration negotiates with 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.”

On Monday, 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.”