Travelers in and around the New York City area are facing extensive travel delays after law enforcement officials discovered a backpack filled with explosive devices late Sunday at a train station in Elizabeth, N.J.

Elizabeth Station , which is just south of Newark Liberty International Airport, serves tens of thousands of travelers and commuters every day. On Sunday night, New Jersey Transit officials closed the Northeast Corridor and North Jersey Coastline rail service overnight, but said both resumed service at around 5:30 a.m. ET. Travelers can expect increased police presence throughout stations along the Northeast.

On Monday morning, Amtrak posted a service alert notifying travelers to potential delays and even cancellations.

“Amtrak Acela Express, Northeast Regional and other services will operate Monday with some schedule modifications,” posted Amtrak.

“Service was suspended Sunday evening due to police activity near the Elizabeth, NJ station and passengers should be prepared for the possibility of additional cancellations and delays throughout the day Monday.”

Amtrak expressed that it  “regrets any inconvenience” caused by the investigation and advised that all travelers contact the rail service to confirm their train’s status or make changes to their plans.

To help combat the traffic issues, New Jersey Transit said that the Port Authority of New York and New Jersey, ferry services and private carrier buses will honor rail tickets and passes.

By Sunday morning, most streets that were closed around Manhattan’s Chelsea neighborhood has reopened, with the exception of West 23rd between Fifth and Eighth Avenues, causing minor commuting delays Monday morning. However, the 23rd Street and 28th Street subway stations near the bombing were both open on Monday, according to New York's Metropolitan Transportation Authority.

The Associated Press contributed to this report.