NEW YORK - Minority police officers and civil rights advocates demanded Tuesday that the city government launch an independent commission to investigate corruption within the NYPD.

The group rallied outside police headquarters at One Police Plaza in downtown Manhattan. Their demand comes in the wake of the recent arrests of four high-level NYPD members in a corruption and bribery probe.

The group also claimed that Latino and African-American officers face harder penalties for minor offenses than their white counterparts. The mayor’s office denied that claim and said all officers receive the same treatment for comparable infractions.

"Some of us get terminated for not filling out a piece of paper, then these gangsters are allowed to collect city taxpayers' money for the rest of their lives," one person said at the rally.

The activists want Mayor Bill de Blasio and City Council to establish an independent commission to fight corruption. They say that if they don't get a response in 30 days, they will take their case to Gov. Andrew Cuomo and state legislators.

A spokesperson for the mayor's office said that the existing Internal Affairs Bureau is "highly effective," and the NYPD is already subject to "an unprecedented level of external, independent oversight from the City Council and an inspector general.