(CNN) -- A security incident at New York's John F. Kennedy International Airport on Monday has federal and local authorities at odds over what happened.
The Port Authority says that 11 people went through an unattended TSA PreCheck security checkpoint at the airport around 6 a.m. Monday.
The TSA alerted Port Authority about the lapse roughly two hours later, according to Joe Pentangelo, the senior police public information officer at the Port Authority of New York and New Jersey. By that time though, they could not find the 11 people as the "travelers in question boarded various flights," Pentangelo said in a statement.
Port Authority police identified three of the passengers who went through the unattended checkpoint through video and sought to identify the remaining eight.
Meanwhile, the TSA called the incident a "possible security incident" and said it had affected just three passengers.
Out of the 11 people walking through the unattended checkpoint, three of them set off the metal detector, reported CNN's affiliates WCBS and WABC.
CNN has sought further clarification over what happened.
The TSA said in a statement: "Early reports indicate 3 passengers did not receive required secondary screening after alarming the walk through metal detector. All personal carry-on bags received required screening. A K9 team was present at the checkpoint at the time of the incident."
A TSA official said it had been determined that the measures taken concerning the three passengers were "all that was necessary."
"TSA works with a network of security layers both seen and unseen. We are confident this incident presents minimal risk to the aviation transportation system," the agency stated on Monday.
The TSA said it would "take appropriate action" once a review was complete.
The incident alarmed some travelers at JFK airport.
"We rely on that to make sure our flight is safe, to make sure everyone on there is not a danger, doesn't pose any danger and we can fly safely," Marianna Iannotta told CNN's New York affiliate WCBS, regarding airport security screening. "So that's a little scary."
The TSA has grappled with security breaches before.
On Saturday, a man forced his way through the exit lane of the security checkpoint at Honolulu International Airport, where he was described as being "combative." He later died after being detained.
Others have slipped past security in a less conspicuous manner.
In 2015, a Texas man without a ticket walked past security checkpoints without being stopped by the TSA, reported the Dallas Morning News. In 2014, a woman known for her repeated attempts to board planes without tickets, slipped through the security checkpoint at San Jose to board a flight to Los Angeles.
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