Eight children and a woman were found dead following a house fire in northwestern Turkey believed to have been caused by a heater, an official said on Wednesday.

The fire broke out late on Tuesday in the first floor of a four-story building in the Yildirim district in Bursa province, Governor Yakup Canbolat said.

The victims, who were Syrian refugees were six siblings aged between 1 and 10, their 31-year-old mother and two cousins aged 10 and 11.

Their father, who was not at home when the fire broke out, reportedly attempted to rescue his family members but was affected by the smoke and hospitalised.

Canbolat said: “Our fire extinguishing teams immediately rushed to the area and tried to put out the fire, but unfortunately, after the fire was extinguished, the picture (they saw) inside was saddening. We were deeply saddened.” He added: “It’s a huge heartbreak. It’s impossible to describe.”

A preliminary inspection of the scene indicates that the fire was caused by a stove heater, Canbolat said. Three neighbours were also hospitalized for smoke inhalation.

Turkey is home to 3.7 million refugees from Syria.