TOKYO (AP) -- Japanese police say more than 40 people have been injured in an explosion at a restaurant in northern Japan.
The explosion occurred in Sapporo, the capital city of Japan's northern main island of Hokkaido.
Police say 41 people were injured, most of them mildly, though one is in serious condition. They are being treated at nearby hospitals.
The cause of the explosion is under investigation. TV footage showed the restaurant in flames.
Police said they had no other details.