SOFIA, March 28 (Xinhua) -- Three patients were killed on Thursday in a fire at a psychiatric hospital in Plovdiv, the second largest Bulgarian city, the Interior Ministry said in a press release.

The fire broke out at midnight, and 60 patients were evacuated, the ministry said.

"After the fire was suppressed, the bodies of three people were found in one of the rooms in the men's ward," the ministry said.

Their identities have not yet been established, it said.

The causes of the fire are under investigation.

Last year, 145 people have died in fires in the country.