An NYPD cop was taken to Kings County Hospital after being stabbed by another officer at their Brooklyn precinct stationhouse — and the department’s Internal Affairs Bureau is now investigating the incident, police sources said.

Both cops were on-duty when one officer assaulted the other following an argument at the 73rd Precinct shortly after 9 a.m. Saturday, the sources said.

The injured officer was being treated for a cut to his left arm, the sources said. The motive for the incident is not known, sources said.