MOSCOW — A fire swept through a Russian home for people with mental illnesses, killing 23 patients and injuring another 23, many of whom were on heavy medication or otherwise unable to walk, the emergency services said Sunday.

The remaining 24 patients were safely evacuated, including some who had to be carried out of the building, and the four medical personnel working at the home were unhurt, they said.

The fire raised additional concern in Russia because it followed two similar fires in 2013 that took the lives of 75 people. After those fires, the government had promised to improve fire safety at institutions for psychiatric patients.

Investigators have not yet determined the cause of the fire, which broke out late Saturday in Alferovka, a village about 350 miles south of Moscow. The fire in the one-story brick building was extinguished shortly after 3 a.m. Sunday.

The fire started in a section of the home dedicated to patients who were unable to walk, emergency services official Igor Kobzev said on Russian state television. He said 39 of the patients in the home could not walk.

All of the patients at the Novokhopersky Neuropsychiatric Home were men and those who died were between 46 and 78 years old, officials said.