A petition is circulating on MoveOn.org that is calling for Mayor Bill de Blasio's resignation in the wake of Saturday's fatal NYPD officer shooting.

The petition gained more than 23,000 signatures in about four hours Saturday. It reads, in part, "NYC residents demand the exit of Mayor Bill de Blasio after 2 NYPD officers were shot and killed... Accountability for his actions and words MUST be handed down."

The petition is expected to be sent to Gov. Andrew Cuomo and the state Legislature in Albany.

According to authorities, Ismaaiyl Brinsley ambushed two NYPD officers as they sat in their patrol car in Brooklyn's Bedford-Stuyvesant neighborhood Saturday afternoon, shooting them at point-blank range in the head. He turned the gun on himself in a nearby subway station. The officers were identified as Rafael Ramos and Wenjian Liu.

By Sunday afternoon, the petition was close to its goal of 50,000 signatures.