Oct. 29 (UPI) -- Human rights organization Amnesty International said Wednesday that a U.S. airstrike that hit a Houthi detention center in Yemen in April should be investigated as a war crime.

The April attack on Saada, in the northwestern part of Yemen, was part of Operation Rough Rider and killed civilian migrants held in a Houthi detention center because of their immigration status, Amnesty said.

The migrants often come through Yemen from the horn of Africa to get to Saudi Arabia for work.

At the time of the attack, the Houthis reported that at least 68 African migrants were killed and 47 were injured.

Related