More than 100 people have died in Yemen after the Saudi-led coalition launched a series of air strikes on a detention centre, according to the International Committee of the Red Cross (ICRC).
The ICRC said that at least 40 survivors were being treated after the attack on Sunday in the city of Dhamar.
Local residents reported hearing six air strikes during the night.
The Saudi-led coalition, which backs Yemen's government, said its attack destroyed a drone and missile site.
The Iran-aligned Houthi rebel movement, which is fighting in opposition to the government and Saudi-led coalition, said the strikes had hit a facility it was using as a prison. The ICRC said it had visited detainees at the location before.
Franz Rauchenstein, the head of delegation for the ICRC in Yemen, said the organisation was collecting bodies from the site and described the chances of finding more survivors as "very low".
Yemen has been at war since 2015, when President Abdrabbuh Mansour Hadi and his cabinet were forced to flee the capital Sanaa by the Houthis. Saudi Arabia backs President Hadi, and has led a coalition of regional countries in air strikes against the rebels.
The coalition launches air strikes almost every day, while the Houthis often fire missiles into Saudi Arabia.
The civil war has triggered the world's worst humanitarian disaster, with 80% of the population - more than 24 million people - requiring humanitarian assistance or protection, including 10 million who rely on food aid to survive.
More than 70,000 people are believed to have died since 2016 as a result of the conflict, according to UN estimates.