WASHINGTON — Amtrak says service has been restored between Washington and Philadelphia, but delays are expected for the next two hours.

Spokeswoman Vernae Graham says a broken overhead power line on a bridge near Aberdeen, Md. forced the rail carrier to switch to diesel trains, causing delays of between one to three hours earlier Sunday. Amtrak says passengers who decided not to travel because of the service disruption can receive a refund or a voucher for future travel.