A fire that broke out in a Madrid nursing home early Sunday killed two women and injured 18 others, Spanish emergency services said.

The blaze broke out at around 7am (0600 GMT) in a room on the first floor of the residence which is home to 39 people, authorities said.

"We found the second floor flooded with smoke and we had to evacuate the residents who were there to a secure place," firefighter Jose Luis Castillo said in a video posted by Madrid's emergency services on X, formerly Twitter.

One of the injured, a woman, was in critical condition due to burns while the rest were taken to hospital with moderate or light injuries, mostly due to smoke inhalation.

"The problem was the evacuation and presence of smoke. Once again, smoke is what ends up causing harm. One of the deaths was due to smoke inhalation," firefighter Roberto Moreira told reporters at the scene.

Spanish media said the women who died, as well as the one in critical condition, were in their 80s.

The cause of the blaze is still being investigated.

"Our deepest condolences for the two who died after the fire in a residence," Madrid mayor Jose Luis Martinez-Almeida wrote on X.