Three thieves smashed through the glass doors of a Park Avenue jewelry store with a sledgehammer before making off with half a million dollars in gems, surveillance video released by the NYPD shows. 

The heist happened around 3:30 a.m. on Saturday at Cellini Jewelers on 56th Street in midtown Manhattan. 

Surveillance video shows the three masked suspects breaking through two glass doors then smashing display cases and grabbing watches and jewelry. 

CRIME, EMPLOYEE SHORTAGES FORCE NYC TO RAMP UP SURVEILLANCE, SOME BUSINESSES TO CLOSE THEIR DOORS

The smash-and-grab burglary lasted just three minutes before the thieves fled in a silver sedan waiting outside the store. 

None of the suspects have been apprehended by police. 

There have been more than 12,000 burglaries so far this year throughout New York City, a 31.5% increase over the same time frame last year, according to NYPD data. 

A similar smash-and-grab targeted Rocco's Jewelry in the Bronx in August, when thieves made off with $2.15 million worth of merchandise. 

The NYPD is offering a $3,500 reward for information leading to the arrests of the suspects in Saturday's heist.