Amtrak said Monday afternoon it was only seeing "minimal delays" along the Northeast Corridor after overhead wire damage halted service between New York City and Philadelphia earlier in the day. But NJ Transit, which also uses the Northeast Corridor rails, was still warning most of its lines were subject to cancellations and delays.

Amtrak spokesperson Jason Abrams said shortly after 3 p.m. that full service had been restored a few hours earlier. Earlier in the day, trains were stopped entirely and then backed up by as much as an hour. Amtrak customers who had reservations on the affected trains would be accommodated on other trains with similar departure times, or could use their tickets another day, and would not incur extra charges for changing their reservations, according to the company.

NJ Transit alerts in the afternoon cautioned trains could be late or canceled along the Northeast Corridor and North Jersey Coast lines — all of its service lines except the Atlantic City line. The Raritan Valley line was originating and terminating at Newark Penn Station. By mid-afternoon, NJ Transit was no longer diverting Midtown Direct service to Hoboken.

NJ Transit rail tickets were being cross-honored by the PATH train at the Newark, Hoboken and Manhattan 33rd Street stations, as well as private carrier buses, according to the rail service.

Abrams said Amtrak was still investigating what caused the overhead wire damage that led to Monday's service issues.

This story has been updated with new information.