Four people were found dead Monday after a fire broke out in a container home in the town of Konitsa in northwestern Greece, authorities said.

Local media reported that the victims are believed to be four elderly siblings – one man and three women – who lived in the container home. Authorities have not officially confirmed their identities, and formal identification procedures are ongoing.

Five fire engines and 10 firefighters from Konitsa and Ioannina responded to the scene and extinguished the blaze.

Investigators from the Fire Service’s investigative division in Ioannina, along with police officers and an ambulance crew, were also dispatched to the site.

The cause of the fire remains under investigation.