An off-duty NYPD lieutenant shot himself in the stomach in Queens on ­Friday, law-enforcement sources said.

Peter Salzone works in the 19th Precinct on the Upper East Side. Officials said the wounds were self-inflicted — adding that they did not know if it was a suicide attempt or an accident.

He was in critical condition after being struck with several bullets.

The shooting took place shortly after 4 p.m. on Clover­dale Boulevard in the Oakland Gardens section.

The wounded cop was at his girlfriend’s house when he shot himself, sources said.

She had left to go to a store and returned to find him wounded, the sources said.

The officer was taken to North Shore University Hospital in Manhasset, LI, where he was in critical condition after surgery, sources said.