Amtrak warned passengers that they should expect delays of up to 90 minutes traveling between New York Penn Station and Newark.

The railroad said there are signal and switching problems near Newark that are causing the delays, which have afflicted travelers for several hours.

Amtrak did not have an estimate for restoration of normal service, but said customers could contact Amtrak for refunds or to rebook.

According to the Associated Press, the delays were also affecting New Jersey Transit trains on the Northeast Corridor, North Jersey Coastline and Raritan Valley lines, which were running 45 to 60 minutes behind schedule.