Neighbours say the Canadian arrested for an attack at a Michigan airport is a friendly, quiet man who lives in a modest apartment in Montreal.

Amor Ftouhi, 49, of Montreal, was arrested Wednesday at Bishop International Airport in Flint, Mich., following an attack on a police officer. He has been charged with committing violence at an airport.

Investigators say the suspect stabbed police Lt. Jeff Neville in the neck with a long knife, and shouted "Allahu akbar" ("God is great") during the attack. He also reportedly said something to the effect of: "You have killed people in Syria, Iraq and Afghanistan, and we are all going to die."

Neville was taken to hospital in critical condition, but his status has been upgraded to stable after undergoing surgery.

Ftouhi was arrested at the scene and appeared in court on Wednesday afternoon. He will remain in custody until a bond hearing next week. Authorities have not ruled out additional charges as the investigation unfolds.

The FBI, which is leading the investigation, says Ftouhi crossed into the United States at Lake Champlain, N.Y., on June 16, and travelled to the airport on Wednesday morning. The attack took place at approximately 9:45 a.m.

"We do know Mr. Ftouhi entered the airport, he spent a little time on the first level, then he went upstairs, he spent some time in the restaurant up there," said David Gelios, the FBI's special agent in charge of the investigation. "Then he came out, he was carrying baggage. He went into a restroom. He spent a little time in the restroom. Dropped both bags and came out, pulled out a knife, yelled 'Allahu akbar,' and stabbed Lt. Neville in the neck."

Authorities say they have no indication yet as to whether his actions are part of a larger plot.

Officials say Ftouhi is a dual citizen of Canada and Tunisia.

Home in Montreal

Police raided Ftouhi's two-bedroom apartment at in Montreal's St-Michel neighbourhood Wednesday, where three individuals were detained for questioning.

Ftouhi's landlord, Luciano Piazza, said Ftouhi has lived in the building for the last six years with his wife and three teenage children. Piazza says Ftouhi worked for him as a part-time caretaker who would clean the stairwells whenever necessary.

"He was a quiet guy," Piazza told The Canadian Press. He said he was surprised by the arrest, as he'd never had any problems with Ftouhi or his family.

"For me, he was a nice person," he said. "I would see him at least once a month, when he paid his rent."

Neighbours echoed those sentiments, telling The Canadian Press and CTV Montreal that Ftouhi was a friendly, quiet person. Many expressed shock over the attack.

Ftouhi told court officials that he has been living in Canada for the last 10 years.

A court pre-trial services officer told the judge that Ftouhi was working "off and on" as a truck driver, but hadn't been working for the last two weeks. Ftouhi did not indicate any mental, physical or substance abuse problems to the court.

Social media presence

A Facebook account that appears to belong to Ftouhi indicates that he was born in Tunisia, where he studied in the faculty of humanities and social sciences at the University of Tunis. He also lists Montreal's College O'Sullivan as part of his education history, and insurance company Industrielle Alliance as his former place of employment.

Nothing has been posted publicly on the account since Feb. 23. Most of the posts are links to discontinued YouTube videos with French and Arabic descriptions. One video describes a method for memorizing the Qur'an. The other explains how to stop someone from swallowing their tongue.

Kamel Yahyaoui, who is listed as one of Ftouhi's friends on Facebook, confirmed to The Canadian Press that he knew Ftouhi. Yahyaoui said Ftouhi wouldn't think of "hurting a fly."

"He's a socially positive person," Yahyaoui said. "He's looking for a good life for him and his family. That's all."

With files from CTV Montreal, The Associated Press and The Canadian Press