Even cops aren’t safe to leave their bicycles unlocked in the city.

This bike cop found that out the hard way yesterday when a brazen bandit swiped his ride outside a Brooklyn store.

The theft prompted calls over the police radio for a “Level One mobilization” — a request for backup units typically reserved for real emergencies.

Officers fanned out across Bensonhurst from the crime scene at 21st Avenue and 86th Street to hunt for the purloined police vehicle — which was clearly marked with the letters NYPD.

Tommy Kwan, owner of Furniture Outlet II, said the cop left his bike unattended when he popped in to say hello at around 3 p.m.

“When he went to leave, the bike was gone,” Kwan said. “He asked if there were surveillance cameras, but we don’t have any.”

In addition to the bike, the cop lost his book of blank police summonses, sources said.