FLINT, Mich. (AP) — A police officer was stabbed in the neck at the Flint airport by a man with a knife Wednesday in what authorities are investigating as a possible act of terrorism.

The attack just before 10 a.m. at Bishop International Airport prompted an evacuation and extra security elsewhere in the city, and a law enforcement official said the FBI is looking at terrorism as a possible motive. A second law enforcement official said authorities are investigating witness reports that the suspect made statements during the stabbing, including saying "Allahu akbar," the Arabic phrase for "God is great."

Both officials spoke on the condition of anonymity because they weren't able to publicly discuss the incident. White House press secretary Sean Spicer said President Donald Trump was briefed on the stabbing.

The condition of the officer who was stabbed, airport police Lt. Jeff Neville, was upgraded from critical to stable by Wednesday afternoon, Michigan State Police Lt. Mike Shaw said. Shaw said one person is in custody and nobody else is believed to have been involved.

Shaw said "everything is on the table" as far as motive is concerned but cautioned against jumping to conclusions. The FBI is leading the investigation. The primarily regional airport, which had been evacuated, is "shut down and secure," Shaw said, and no other threats had been identified.

In an official statement, the FBI said it's aware of the reports that an attacker made statements during the stabbing, but added that it's too early to determine their nature or whether the incident was an act of terrorism.

Witnesses described seeing the suspect led away in handcuffs by police, Neville bleeding and a knife on the ground.

"The cop was on his hands and knees bleeding from his neck," Ken Brown told The Flint Journal. "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 the attacker being led away in handcuffs. She described the man in custody as appearing "blank, just totally blank."

Genesee County Commissioner Mark Young said he spoke with Neville's family at a hospital following the attack and that the wounded officer had just come out of surgery.

Young retired from the Genesee County sheriff's office in 1997 and said his "good friend" Neville did the same two years later. He said Neville served in various capacities with the sheriff's office including in the jail, on road patrol and as a court officer. Neville retired from that department as a lieutenant.

Young said he headed to the airport when he learned about the stabbing Wednesday. He said once he got there, he "tried to assess and work with emergency management and emergency response teams from the sheriff's department, kind of trying to see what was going on."

"Things were chaotic, but very well organized and under control — how the sheriff's department was handling things and how Bishop International was handling things," he said.

A few miles away, officials stationed police officers at Flint City Hall after the incident. Mayor Karen Weaver said in a release the situation was "under control" but that officials sought to take "extra precautions."

Flint is about 50 miles northwest of Detroit.