Ten people, including Japanese tourists, were killed and seven other injured Saturday in a fire that engulfed a second-story indoor shooting range in Busan, the nation's second largest city, Yonhap News Agency said.

The fire in the port city broke out Saturday afternoon. Most of the dead were believed to have died from severe burns, police said.

Yonhap said several Japanese are believed to be among those killed and injured, citing an unnamed police officer, who said the death toll may rise due to the serious conditions of those hospitalized.

Authorities are investigating the cause of the fire.