A fire during a rock concert killed at least 27 people in a nightclub in Bucharest, Romania Friday.
Romanian officials say 145 people were taken to hospitals with burns.
Between 300 and 400 people were in the old, Soviet-era building at the time, watching a free concert in the Colectiv nightclub by the heavy-metal band Goodbye to Gravity.
Initial reports said the flames were caused by a fireworks explosion, but later reports say there is no evidence of a blast. Witnesses said fireworks used during the show set the ceiling ablaze.
The flames caused a panic among the several hundred patrons, mostly young adults, who were gathered at the club. The only escape route for panicked clubgoers was a basement door. Some of the injured were trampled in a stampede for the sole exit door.
A person injured during the fire is carried on a stretcher at the emergency hospital.
Romanian Prime Minister Victor Ponte broke off a visit to Mexico to return home. He declared three days of national mourning beginning Saturday.
President Klaus Iohannis comforted survivors in the hospital, and visited the nightclub later Saturday. The president placed flowers outside the building, as police and forensics experts searched for clues and investigated inside.
Iohannis said it was "a very sad moment for our nation."
Police have begun an investigation.