Story highlights A TSA officer coming on duty spotted two devices

That started events that resulted in the NYPD bomb squad being called

The devices had been removed from a traveler's bag earlier but were not a threat

The bomb squad was called "out of an abundance of caution," the TSA says

A New York airport screener who removed two pipes from a traveler's bag and set them aside Monday morning prompted a security scare six hours later when the next shift saw the pipes and feared they might be pipe bombs, local and federal officials said.

The incident at New York's LaGuardia Airport began at 11:30 a.m. when a screener discovered unidentifiable items inside a passenger's carry-on bag. The officer screened the item for explosives, determined them not to be a threat and cleared the passenger through the checkpoint, a Transportation Security Administration official said.

But the officer prevented the metal item from going through because of its "material and appearance," a TSA official said.

When the next shift arrived, one officer saw the items and mistakenly believed they were test objects, used to check screener proficiency. When that officer later learned they were not test items, the officer alerted others, and the TSA contacted the Port Authority Police Department, responsible for protecting the airport.

"No one could give a good account of what it was, so we did the safe thing and called (the) NYPD bomb squad," Port Authority Police Department spokesman Al Della Fave told CNN.

The bomb squad removed the devices at 5:30 p.m. -- six hours after they were taken from the passenger.

The devices were taken to a remote location for examination or disposal, one official said.

"We have still not been told what it was or what it was composed of," Della Fave said.

Several law enforcement sources told CNN the objects were determined to be homeopathic medical devices.

TSA officials said the checkpoint was not closed, nor was the terminal evacuated, during the incident. The bomb squad was called "out of an abundance of caution," the TSA said.

Port authority spokesman Della Fave said the police force will "speak with their (TSA) supervisors to determine how or why this breakdown in communications took place so it won't happen again."