At least 25 people, including patients, have been killed and more than 100 others were injured in a fire at the Jazan General Hospital in southwest Saudi Arabia on Thursday, according to BBC.

The deadly fire broke out on the first floor of the hospital in the early hours of Thursday, the Saudi civil defense agency said in a statement, according to Al Jazeera.

The intensive care unit (ICU) and the maternity ward, both located on the first floor, were completely destroyed in the fire. More than 20 fire brigades were called in to douse of the fire as well as dozens of civil defense personnel involved in the rescue operation.

The fire has been put under control, officials said. Those injured have been rushed to nearby hospitals and some of them are reportedly in critical condition.

Authorities have also launched an investigation to find the cause of the incident. "Jazan hospital accident is now over and investigation is underway to find out its reasons," officials said, according to AFP.

Saudi local media, however, claimed that more than 30 people have died in the fire, according to Daily Capital.

Jazan is a port city and also capital of southwest Saudi region of Jizan, bordering Yemen.