At least 12 people are dead and more than 20 missing after a fire tore through a psychiatric institution early Friday outside the central Russian city of Veliky Novgorod, Russian state news agency RIA Novosti cited local officials as saying.

A criminal case has been opened to look into the cause of the fire, according to a statement on Russia’s Investigative Committee’s website.

A total of 59 people were inside the building when the fire broke out, the Health Ministry said, according to RIA Novosti. The Emergencies Ministry said 23 people have been rescued, according to the news agency.

Police are searching the area for residents who may have fled the site, it said.

The fire has now been extinguished, the news agency said, and dozens of emergency personnel are working at the scene.