NEW YORK (CBSNewYork) — The NYPD was investigating late Sunday after a haunting verbal assault from what is supposed to be a police-only radio frequency.

At 5:42 p.m. Saturday, a message was broadcast across several divisions of the NYPD radio frequency asking to talk to a captain assigned to the Midtown South Precinct, police sources told CBS2.

The separate messages went on for several minutes, sources said.

First, there was a false call that a police officer had been shot in the Bronx, 1010 WINS’ Carol D’Auria reported. Sources said at one point, the unauthorized person directed his broadcast at a specific captain from Midtown South, CBS2’s Hazel Sanchez reported.

He said: “South Duty captain to Central. Remember you put me in jail? I’m out now and I am going to put a bullet in your head.”

In another instance, the man said, “Remember, captain, I’m coming for you.”

In a third, the suspect said: “Captain, captain, oh captain, oh captain, oh captain, oh captain, I’m gonna put a bullet in your mother too, son.”

An officer responded: “Hey, grow up. Some people are trying to do their job on this division.”

The person did not identify himself by name, source said.

The threats have been deemed not credible at this time, sources said.

The other unauthorized radio calls have involved yodeling or nonsensical sounds, 1010 WINS’ D’Auria reported.

There were no threats made on Sunday. Police do not believe the unauthorized person stole a police radio, sources said.

The NYPD said it does not comment on security matters, but said appropriate actions are being taken.

Investigators were reviewing the messages late Sunday.