THE BRONX - NYPD Commissioner Bill Bratton condemned the use of illegal dirt bikes and ATVs, calling their drivers "nitwits" and "knuckleheads" at a news conference Tuesday.

Bratton announced a crackdown on their use, which he described as dangerous behavior.

He also called on residents to report neighbors who store and use them.

Along with the announcement, police used bulldozers to crush around 70 seized vehicles. They say they've seized hundreds more and made dozens of arrests.

Police say five people died last year using off-road vehicles on city streets.