Six members of the same family, including three children, died early Saturday at a rural home in the northern Spanish town of Tordomar, authorities told Efe.
Five other people inside the residence - three adults and two minors - were injured in the blaze, which broke out at around 2:30 a.m., Jose Maria Arribas, a representative of Spain's central government in Burgos province, said after visiting the site of the tragedy.
Those five individuals were receiving treatment at the Burgos University Hospital and are reportedly out of danger.
In addition, several people who tried to help rescue people inside the house also sustained lesser injuries.
The six victims apparently died of smoke inhalation as opposed to burns, Arribas said, adding that investigators believe the blaze may have been caused by a faulty chimney.
Some nearby wood furniture caught fire, as did some plastic objects that released toxic smoke.
Tordomar Mayor Inmaculada Sierra said the rural home was occupied by 12 people belonging to the same family, five children and seven adults, who lived in Madrid and had gone to the rural house for "a celebration."
More people could have died had one person inside the house not woken up, run to a bar located across the street and enlisted the assistance of several young people, who helped pull those affected by smoke inhalation out of the residence. EFE