The Houthi militia, which is backed by Iran, said the attack was an American strike. The U.S. Defense Department said it was assessing the claims and took them seriously.

Yemen’s Houthis alleged that a U.S. strike hit a migrant detention center in Saada, killing 68. There was no immediate comment from U.S. Central Command.

Yemen’s Houthi rebels on Monday alleged a US airstrike hit a prison holding African migrants, killing at least 68 people and wounding 47 others. The US military had no immediate comment.