Officials on Wednesday evacuated an airport in Flint, Michigan, where a witness said he saw an officer bleeding from his neck and a knife nearby on the ground.
On Twitter, Michigan State Police say the officer is in critical condition and the FBI was leading the investigation.
A law enforcement official later said the FBI is looking at terrorism as a possible motive in stabbing.
The FBI said the alleged airport stabber referred to people being killed in Syria, Iraq and Afghanistan during the attack.
Bishop International Airport posted on Facebook that passengers were safe and were being told to check for flight delays or cancellations.
Ken Brown tells The Flint Journal he was dropping off his daughter at the airport and saw the officer bleeding from his neck. He says 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,” 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, tells Flint TV station WJRT she saw the attacker being led away in handcuffs. She described the man in custody as appearing “blank, just totally blank.”
Airport and police officials didn’t immediately respond to messages from The Associated Press seeking comment.
Flint is about 50 miles northwest of Detroit.
Story by the Associated Press