KOLKATA, India, Nov. 20 (Reuters) - A powerful explosion ripped through a train in eastern India on Monday, killing five people and wounding 25 seriously, police said. The explosion hit two crowded coaches near a remote railway station in West Bengal state, about 665 km (415 miles) north of state capital Kolkata, Raj Kanojia, a top police officer, told Reuters. "It seems to be a powerful bomb and the casualties could mount in the next few hours," Kanojia said.