Most of the victims of a powerful gas explosion and fire in Tokyo's Kabukicho entertainment district early Saturday morning were dead before they reached hospitals in the metropolitan region, leaving doctors with no chance of saving them.

"I didn't know what to do (with patients) as they apparently had died (in the fire)," said a doctor at the International Medical Center of Japan in Tokyo's Shinjuku Ward, close to the four-story building where 44 people were killed.

Three men arrived at the hospital around 1:45 a.m., but two had suffered serious burns to the upper half of their bodies and were already dead, the doctor said.