(Reuters) – Bishop International Airport in Flint, Michigan, was evacuated on Wednesday after a police officer was stabbed in the neck in what a U.S. government official familiar with the situation said was being investigated as a possible act of terrorism.

All passengers were safe, the airport said in a brief statement on its Facebook page. The officer who was stabbed is Lieutenant Jeff Neville of the Bishop International Airport Department of Public Safety, Michigan State Police spokeswoman Lori Dougovito said by telephone.

Neville underwent surgery after the attack and is stable, Dougovito said. Asked if the stabbing was under investigation as possible terrorism, the government official, who asked not be named, said “yes.”

The officer was stabbed inside the airport’s main terminal, Michigan State Police spokesman David Kaiser said in a telephone interview from the airport.

“We are aware of reports that the attacker made statements immediately prior to or while attacking the officer, but it is too early to determine the nature of these alleged statements or whether or not this was an act of terrorism,” the Federal Bureau of Investigation’s Detroit field office said in a statement.

Police have taken a “person of interest” into custody, Flint Mayor Karen Weaver said in a statement. Officials increased security at Flint City Hall, including additional police officers, in “an abundance of caution,” the statement said.

Bishop Airport is a small regional airport with two runways that has, on average, 16 commercial flights arriving or departing each day, according to FlightAware, a flight tracking service.

The airport warned of potential cancellations and delays after the incident.

(Reporting by Jonathan Allen in New York; Additional reporting by Timothy Mclaughlin in Chicago and Mark Hosenball; Editing by Paul Simao and Tom Brown)