The Bishop International Airport (FNT) in Flint, Michigan has been evacuated after a police officer was stabbed in the neck. The suspect, Amor Ftouhi, is in custody, and the airport closed for several hours. The FBI is investigating the incident for terrorism.

Police have identified the knifeman as 50-year-old Amor Ftouhi, a Canadian resident. Before critically stabbing Lieutenant Jeff Neville, who is now in stable condition and expected to make a full recovery after surgery, Ftouhi entered the airport on its first level, police told reporters.

Ftouhi spent some time in a second floor restaurant and went inside a restroom, then upon returning, dropped two bags, took out a knife, yelled, "Allahu akbar" and stabbed the officer, police said.

Police also thanked Canadian partners for helping in the investigation. Canadian media has reported police raids in Montreal are related.

An FBI official told reporters that a terrorism investigation is underway, and that Ftouhi yelled about people being killed in Syria, Iraq and Afghanistan, and that everyone would now die.

Lieutenant Neville "never stopped fighting" the suspect until he was handcuffed, one of the arresting officers told reporters.

According to a probable cause affidavit, Ftouhi asked why he wasn't killed once subdued by law enforcement.

Ftouhi is charged with committing an act of violence at an airport, acting US Attorney David Lemisch of the Eastern District of Michigan, told reporters.

The Canadian government said in a statement that it “condemns this heinous and cowardly act. Our thoughts and sympathies are with the officer and his loved ones.”

US Attorney General Jeff Sessions released a statement, saying, "I want to assure all our law enforcement across the nation, any attack on someone who serves and protects our citizens will be investigated and prosecuted to the fullest extent of the law. I am proud of the swift response from the FBI and our federal prosecutors and their partnership with local police and the Canadian authorities. Our prayers are with the officer and his family for a full recovery."

All passengers are safe and have been evacuated, the airport said in a statement, urging flyers to check with their airlines for potential cancellations or delays.

The injured officer was identified as Lieutenant Jeff Neville. The the suspect is Canadian-born and yelled out “Allahu Akbar” as he stabbed Neville, NBC News reported citing “multiple law enforcement sources.” The attack is being investigated as a possible act of terrorism.

NBC News: The Canadian born suspect shouted "Allahu Akbar" before stabbing the officer multiple law enforcement sources say. W/ @anblanxhttps://t.co/TYSZIgmFQE — Tom Winter (@Tom_Winter) June 21, 2017

“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 FBI said in a statement on Wednesday afternoon, adding that law enforcement officers were questioning the suspect in an effort to “determine the nature and motive for the attack.”

“Based on the information that we have at this time, we believe this to be an isolated incident. We currently have no specific, credible information that there is a threat to the Flint community,” the FBI said.

The incident happened on the second floor of the main terminal, around 9:45 am local time on Wednesday, according to WNEM-TV.

"The cop was on his hands and knees bleeding from his neck," Ken Brown, who was dropping his daughter off at the airport, told MLive. "I said they need to get him a towel."

Brown added that he saw a man getting detained by police, and a knife on the ground near the injured officer.

Another witness, Cherie Carpenter, told WJRT-TV she saw the attacker’s face as he was being led away in handcuffs, and that it was “blank, just totally blank.”

Neville was critically injured, according to Michigan State Police. His condition was later upgraded to stable.

. The FBI is the lead agency in this incident. MSP is providing resources to our Federal and local partners as this scene progresses. — MSP Metro Detroit (@mspmetrodet) June 21, 2017

More than 20 police vehicles have responded to the incident, including Flint, Burton and Michigan State Police, local media reported. The FBI has taken the lead role in the investigation.

Police have been stationed around the Flint City Hall complex out of an abundance of caution, Mayor Karen Weaver said.

UPDATE: Mayor Weaver says Flint City Hall on "heightened security" in connection to Bishop Airport stabbing pic.twitter.com/TN3GN1AiL1 — NBC25 / FOX66 News (@nbc25fox66) June 21, 2017

Bishop is the third busiest airport in Michigan, serving 787,000 passengers in 2016.