UN condemns deadly air strike on Yemen prison
People have been searching for survivors amid the ruins of the prison
The UN has condemned an air strike on a Yemen detention centre that has killed more than 70 people.
The facility in Saada, a stronghold of the rebel Houthi movement in north-western Yemen, was hit on Friday.
UN Secretary General Antonio Guterres said in a statement that the "escalation needs to stop".
In a statement on Saturday, the Saudi-led coalition fighting Houthi rebels in the country denied it had carried out the air strike.
The coalition also said the site was not on a list of targets to avoid that had been agreed with the UN and had not been reported by the Red Cross.