Jittery Midtown residents, apparently on edge in the wake of Sept. 11, called the cops when they heard explosions late last night – but it turned out the big booms were part of an NBC fireworks display.

A firetruck with sirens wailing arrived at the peacock party at 30 Rockefeller Center, where NBC bigwigs were celebrating the network’s 75th anniversary, within minutes of the fireworks, whose thundering booms could be heard blocks away.

But the firefighters were immediately turned away, since the network had permission to shoot off the rockets, which went off at around 11:15 p.m., and again at midnight.

“Some people called who were afraid of the noise, but it’s OK,” said one firefighter at the scene. “We knew about it.”

Fire officials said they are obligated to dispatch a truck whenever they receive a call.

“You can never assume anything – you gotta send the troops,” an FDNY spokesman said.