Medecins Sans Frontieres (MSF) says one of its hospitals in northern Yemen has been destroyed by several air strikes.
The first, which occurred around 22:30 (19:30 GMT) on Monday, hit part of the facility in Saada province that was not being used, according to the charity.
All staff and patients had been evacuated by the time the second strike hit about 10 minutes later.
However, the Saudi-led coalition battling Yemen's Houthi rebel movement denied that it had bombed the hospital.
Asked by the Reuters news agency if he knew what had caused the blasts, spokesman Brig-Gen Ahmed al-Asiri said: "We cannot tell without investigation."