Passenger train service in the Northeast rail corridor was disrupted Sunday by an electrical breakdown that stranded some travelers inside a Hudson River tunnel for two hours and blocked trains in and out of Manhattan.

Damage to overhead electrical wires stopped an NJ Transit train around 8:30 a.m. in one of the two tunnels linking New Jersey and New York's Pennsylvania Station, the New Jersey transit system said.

Passengers on that train, which was headed into Manhattan, had to wait until they could be transferred onto another train in the tunnel, and didn't reach Penn Station until shortly before 11 a.m., NJ Transit spokesman Dan Stessel said.

The ripple effect of the shutdown was soon felt as southbound Amtrak trains arriving from Boston backed up at Penn Station, and northbound trains from Philadelphia and other points south had to halt at Newark, N.J. The second tunnel to Penn Station had already been closed for routine maintenance.

An Amtrak spokeswoman, Tracy Connell, said she did not know how many Amtrak trains or passengers were affected by the impasse. Amtrak normally carries about 36,000 passengers a day in the Northeast Corridor, but fewer on weekends, she said.

The Tuesday and Wednesday before Thanksgiving are historically the rail system's heaviest travel days of the year, but the Sundays before the holiday are not noticeably busier than other Sundays, Connell said.

Amtrak and NJ Transit share the tracks between New York and Newark.

Neither NJ Transit nor Amtrak could immediately describe the nature of the malfunction that halted traffic.

In the meantime, Amtrak and NJ Transit tickets were being honored by PATH trains, which provide commuter service through tunnels entering lower Manhattan, between New York and Newark.

Amtrak carries about 69,000 customers a day nationwide, about half of those in the Northeast corridor.