The fishplate was found open by gangmen who informed railway officials at the Telia halt, Banka Station Manager C D Khalko said.
The Banka-Patna Intercity Express was stopped and the train was allowed to leave only after the fishplate was rectified by railway engineers after about two hours, he said.
The train service on Banka-Barahat railway station remained suspended for nearly two hours, Khalko said.