A US air strike in Yemen that killed more than 60 African migrant prisoners should be investigated as a possible war crime, Amnesty International said today.

The attack in Saada province last April was part of an intense US bombardment targeting the Houthi movement in response to its attacks on shipping passing through the Red Sea corridor.

The US military’s Central Command has yet to offer any explanation for the April 28 strike on the prison, which had previously been hit by a Saudi-led coalition also fighting the Houthis. It had been known to hold African migrants who were detained while trying to reach Saudi Arabia through the war zone.

After the strike, the Houthis displayed debris that was probably from two, 250-pound precision-guided GBU-39 small-diameter bombs used by the US military, Amnesty said.

Survivors interviewed by the human rights group, all Ethiopian migrants detained while trying to reach Saudi Arabia, said they had seen no Houthi fighters posted inside the building.

Amnesty said the strike appeared to be “indiscriminate” as there was no clear military objective.

The Houthis recently put the death toll from the attack at 61, lower than the 68 initially reported, the rights group said.

The Saudi-led coalition’s strike on the same compound took place in 2022, causing a collapse that killed 66 detainees and wounded 113, a United Nations report found. The Houthis shot dead 16 detainees who fled after the strike and wounded another 50, according to the UN.

The US air strikes on power stations, mobile phone infrastructure and military targets in Yemen began under president Joe Biden but sharply escalated under current White House occupant Donald Trump.

Activists say the attacks killed civilians, highlighting an April strike on an oil depot that claimed more than 70 lives.