State police in Michigan said an officer had been stabbed in the neck at the Flint airport Wednesday morning and that a 50-year-old Canadian shouting in Arabic was taken into custody.
Law enforcement officials said the FBI was investigating the attack on Lt. Jeff Neville at Bishop International Airport as an act of terrorism.
Witnesses told authorities that the suspect, identified as Amor Ftouhi, shouted the Arabic phrase, “Allahu akbar,” which loosely translates to “Allah is the greatest” in English.
The FBI said the attack was believed to have been an “isolated incident.”
The airport was evacuated and shut down.
The airport Facebook page said passengers were safe and were being told to check for flight delays or cancellations.
Neville underwent surgery and was in stable condition.
Authorities recovered the knife, which had a long serrated blade and said Ftouhi was restrained immediately after the attack and that Neville helped stop further harm to himself.
Ftouhi entered the United States last month.
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,” Brown said.
“I said they need to get him a towel.”
White House press secretary Sean Spicer said Homeland Security Adviser Tom Bossert briefed President Donald Trump on the attack.
Flint is about 50 miles north of Detroit. The city has drawn national attention for a 2014 water crisis.
Money-saving measures resulted in tainted drinking water for the city of over 98,000, affecting the health of thousands.
The Associated Press contributed to this report.