At least 10 people were killed after a fire broke out in a retirement home in the northern Spanish town of Villafranca de Ebro early Friday, authorities said.

The blaze started in one of the rooms, Fernando Beltran, the national government's top official in Aragon region, told reporters.

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All the victims were elderly people living in the Jardines de Villafranca residence, a care home for people with mental health issues, Aragon regional president Jorge Azcon told reporters.

One person was in a critical condition and another was in a serious condition, Azcon said.

The fire started at around 5 a.m. local time, and it took about two hours for firefighters to extinguish it, a spokesperson for the regional government said.

Firefighter chief Eduardo Sanchez told reporters the fire was contained to the room where it started and that the fatalities were caused by smoke inhalation.

"The doors were closed, they prevented the fire from spreading. The tragedy could have been worse," Azcon said after visiting the building.

Several residents were treated, mainly for smoke inhalation, mayor Volga Ramirez said.

Authorities have opened an investigation into the cause of the fire.

Azcon said the priority now was to transfer the residents who were not injured in the blaze to another care home in nearby Huesca.