BUCHAREST, Romania -- Authorities say 38 people have received hospital treatment after a fire broke out at a popular nightclub in the Romanian capital.

The fire erupted early Saturday at the upmarket Bamboo nightclub in northern Bucharest. There was no word on what caused the fire.

About 20 ambulances rushed to the scene as revelers ran outside. Bogdan Oprita, coordinator of the capital's ambulance service, said most of the injured were suffering from smoke intoxication.

Senior emergency situations official Raed Arafat said one person was seriously injured and some used their own transport to reach hospitals. There were unconfirmed reports that people were smoking at the club, which is illegal.

Some 64 people died at a fire at a nightclub in Bucharest in October 2015, the worst fire in the country's history. (AP)