NEW YORK (CBSNewYork/AP) — Metro-North Railroad trains were delayed up to 90 minutes as police investigated an unattended bag.

The bag was found on a bridge over the Harlem River at 138th Street that’s only used by trains, railroad spokesman Aaron Donovan said.

The problems began around 8:15 a.m. and affected commuters to and from Grand Central Terminal in Manhattan.

A conductor on one train told passengers that the bag was hanging off the bridge.

Check the Metro-North website for the latest service updates.

Donovan said the situation was declared safe around 9:30 a.m. after police with dogs checked out the bag.

It wasn’t clear how the bag got there, or what was in it.

(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)