Fire at a retirement home in eastern Bulgaria killed four residents, making it the country’s latest care facility disaster Police confirmed on Sunday.

According to regional police spokeswoman Petya Kupova, an 88-year-old woman and three males aged 73-78 died in the nighttime blaze in the city of Varna.

An 83-year-old woman was clinging on to life, Kupova said.

Investigators have not ruled out arson by a resident suffering psychiatric problems at the home which lacks care staff, particularly at night.

Last July, four people died in a fire at another home with the same owner and in November, nine people perished at a home also in the Varna region.

Probes into those fires are still underway but prosecutors have said numerous rules were being broken in retirement homes around the region.

The latest fire comes after relatives of residents of a psychiatric clinic complained of mistreatment and even deaths immediately after their admission.

Despite 25 years of reports on the problem from the Council of Europe’s Committee for the Prevention of Torture, Bulgaria’s “chronic incapacity” to undertake reforms to modernize social and mental care homes was highlighted in November by the Council of Europe.