Arab coalition warplanes struck a prison in the Yemeni city of Hodeidah, killing 45 people including inmates, a local official, relatives and medical sources in the Houthi-controlled Red Sea port said on Sunday.
The prison in the city's al-Zaydiyah district was holding 84 prisoners when it was struck three times late on Saturday, the sources said.
The Saudi-led coalition has been fighting Houthi rebels since March 2015 to try to restore to office internationally-recognized President Abd-Rabbu Mansour Hadi, who was sidelined from power by the Iranian-allied group in late 2014.
There was no immediate comment from the coalition.
At least 17 civilians were killed in the southwestern province of Taiz on Saturday by a coalition air strike that struck a house, officials and residents said.
The exiled Hadi on Saturday rejected a U.N. peace proposal to end the turmoil saying the deal would only be a path to more war and destruction.
Speaking after meeting U.N. envoy Ismail Ould Cheickh Ahmed in Riyadh, Hadi said the agreement would "reward the rebels and penalize the Yemeni people and legitimacy", according to the government-controlled Saba news agency.
According to a copy of the proposal seen by Reuters, the plan would sideline Hadi and set up a government of less divisive figures.