FBI investigating terrorism link as US airport evacuated after officer stabbed in the neck
Officials have evacuated an airport in Flint, Michigan, where a witness said he saw a police officer bleeding from his neck and a knife on the ground nearby.
Michigan State Police said the officer is in a critical condition and the FBI is leading the investigation.
A law enforcement official says the FBI is looking at terrorism as a possible motive in the stabbing of an officer at Flint airport.
Bishop International Airport posted on Facebook that passengers were safe and were being told to check for flight delays or cancellations.
Ken Brown told The Flint Journal he was dropping off his daughter at the airport and saw the officer bleeding from his neck.
He said he saw a man detained by police and a knife on the ground.
"The cop was on his hands and knees bleeding from his neck," Mr Brown said. "I said they need to get him a towel."
Cherie Carpenter, who was awaiting a flight to Texas to see her new grandchild, told Flint TV station WJRT she saw a man being led away in handcuffs.
She described the man in custody as appearing "blank, just totally blank".
Flint is about 50 miles north-west of Detroit.
The airport released a statement confirming the incident.
"All passengers are safe and are being evacuated at this time. Please check with your airline for potential cancellations or delays."