The medical charity MSF says that an ambulance for an MSF-supported hospital was hit in an airstrike in Yemen as rebels and security forces say dozens have been killed in one of the most intense 24 hours of airstrikes since the Saudi-led coalition began its military campaign.

MSF says that the ambulance driver was killed in an airstrike on the northern town of Dahyan on Thursday. The media center of the Shiite Houthi rebels says that 26 people were killed during the bombing of Dahyan.

Officials say 22 were killed in strikes on the capital, Sanaa.

The officials spoke on condition of anonymity because they were authorized to speak to the press.

Since the beginning of the air campaign in March 2015, more than 5,800 people have been killed.