A toy grenade found at an East Harlem subway station Friday shut down service during rush hour and prompted an NYPD Bomb Squad investigation. The grenade turned out to just be plastic, police sources said.

The device was initially believed to be a real grenade. It was discovered on the southbound No. 4 train tracks at Lexington Avenue and 125th Street around 8:45 a.m. Friday. Service for the Nos. 4 and 6 trains were halted between Manhattan and the Bronx in both directions as the Bomb Squad and Emergency Service Unit investigated. Some southbound trains in The Bronx made their final stop at Hunts Point Avenue.

On the east side of Manhattan, No. 5 train service was suspended. The Bronx and Manhattan and northbound trains rerouted to the 2 line between Nevins Street in Brooklyn and 149th Street-Grand Concourse, the MTA said. By around 10 a.m., the device was found to be a harmless piece of plastic, sources said.

The MTA confirmed that service had been restored. This is a developing story.