At least 155 people were injured in a powerful earthquake that struck central Japan today, hospital officials said.At least 100 received treatment at Kariwa-gun Sogo Hospital after being hurt in the quake, while another 55 people were taken to other hospitals in the region, the officials said."We are asking hospitals in other regions to send doctors as the medics here alone cannot handle things," said Yoshiko Abe, an official at Kashiwazaki Hospital, where some 40 people received treatment following the quake.It was not immediate known how serious the injuries were, but news reports said some of them were in serious condition.Television footage showed damage to a number of buildings across central Niigata prefecture, including Japanese-style wooden homes whose roofs collapsed with rubble strewn across the ground.Footage also showed a bridge that suffered cracks and shops where groceries tumbled to the ground.