At least 31 people died and more than 100 were injured after a massive fire broke out on Thursday in a hospital in Jazan, a city in Saudi Arabia’s southern coast. The Saudi civil defence directorate posted on Facebook that the fire started at about 2.30 am local time. The flames started spreading around Jizan General Hospital from the first floor, Al Jazeera reported. The cause of the fire has not been determined yet.

The hospital’s Intensive Care Unit and and maternity ward were said to be located on the first floor. Saudi Arabia authorities said they had dispatched 20 fire teams to douse the fire, and rescue operations are underway. The civil defence directorate had tweeted earlier that the fire was under control and officials were looking into what started it.