A Reuters witness at the scene of the attack in the Abs district said medics could not immediately evacuate the wounded because war planes continued to fly over the area and first responders feared more bombings.
The facility is run by aid group Medecins Sans Frontieres, which confirmed on its official Twitter account that an air strike had occurred there but said the number of deaths and injuries remained unclear.
A spokesman for the Saudi-led coalition did not immediately respond to a request for comment on the reported attack.
Another air attack hit what MSF described as a school in neighbouring Saada province on Saturday, killing 10 children, but the coalition said the bombing had targeted a training facility run by Yemen's dominant Houthi movement.
Dozens of air strikes have hit civilians in Yemen since a coalition of Arab states led by Saudi Arabia began military operations in March 2015 to restore President Abd-Rabbu Mansour Hadi to power and roll back gains by the Iran-allied Houthis.
The scene after the hospital run by Medecins Sans Frontieres in the province of Hajja is hit by Saudi-led air strikes. Reuters.
A Saudi-led coalition air strike hit a hospital in Yemen's northern Hajja province on Monday, residents and local officials said, killing at least seven people and wounding 13.
