A Port Authority police officer apprehended a man who police say was threatening a cab driver with a knife.

According to police, a Port Authority sergeant was driving up to the bus terminal on 42nd Street in Manhattan when he was almost sideswiped by a cab around 2:45 p.m.

Police say the officer noticed that the driver appeared to be fighting with his passenger, who was trying to exit the cab without paying.

Police say that passenger was threatening the driver with a knife.

The Port Authority officer apprehended the passenger with help from the driver and an unknown civilian, and then turned him over the the NYPD.

The passenger has been charged with criminal possession of a weapon and resisting arrest, among other charges.