Cops shot and critically injured a knife-wielding maniac at a Manhattan apartment building Sunday afternoon, law-enforcement sources said.

Officers were called to a home at 126 Ludlow St. on the Lower East Side over a domestic dispute when the man charged at cops with a large knife around 4 p.m,  sources said.

One of the cops fired a shot and gravely injured the man, according to the sources.

Medics rushed the suspect to NYC Health + Hospitals, where he is listed in critical condition.

A witness was also left wounded, according to sources. It’s unclear what their condition was as of Sunday afternoon.

Police recovered the knife at the scene, the NYPD said.

This is a developing story. Please check back for updates.