Alexandre Bissonnette, the 27-year-old accused of opening fire on a Quebec City mosque, has been charged with six counts of first-degree murder and five counts of attempted murder while using a restricted firearm.

During a brief court appearance Monday evening, Bissonnette, wearing handcuffs, frequently cast his eyes toward the ground and avoided turning toward the packed gallery.

He will remain in custody until his next court appearance on Feb. 21.

Provincial police are treating the attack as a terrorist act. RCMP spokeswoman Camille Habel said Bissonnette could later face terrorism-related charges, depending on the outcome of the ongoing investigation.

Six men were killed and five people remain in hospital with injuries.

Two of the surviving victims will need more surgery, while the other three are stable and may be discharged soon. Another 13 people with minor injuries have been released, according to a hospital spokeswoman.

'Introverted young man'

On Monday afternoon, Laval University confirmed that he is a student, and is now barred from all activities effective immediately until all judicial proceedings are over.

His employer, Héma-Québec, issued a statement saying the organization is "shocked" to learn that he was among their employees. Bissonnette was a member of their call centre team.

This screengrab from the suspect's Facebook page, taken before it went offline, shows Alexandre Bissonnette as a child wearing his cadet uniform. (Facebook) "As an organization whose primary mission is dedicated to the gift of life, these events have sent a shock wave through the organization," the non-profit agency said.

According to Bissonnette's Facebook page, which has since been taken down, Bissonnette is from the Quebec City suburb of Cap-Rouge. He was also a cadet as a child.

Neighbours of Bissonnette's parents said he was renting an apartment with his twin brother near the Centre Culturel Islamique de Québec, where the shooting took place Sunday evening.

Neighbour Réjean Bussière said Bissonnette was very introverted.

"He's a very closed-off young man," Bussière told CBC's French-language network, Radio-Canada.

Only 1 suspected shooter

Another man, Mohamed Belkhadir, was arrested outside the mosque within minutes of the shooting. He was released after police confirmed he was a witness and not involved in the shooting.

He said he had been shovelling snow when he heard gunshots — when they stopped he entered the mosque to call 911.

"I saw the image of someone with a firearm, I didn't know it was police. I thought it was a shooter who'd returned," Belkhadir told Radio-Canada.

The man fled and police arrested him. He was released Monday.

Shortly after noon Monday, provincial police said that man was no longer a suspect, but rather a witness to the attack.

A half-hour after the shooting, Quebec City police Insp. Denis Turcotte said a second man called 911 indicating that he wanted to co-operate in the investigation.

La SQ confirme qu’un seul des individus arrêté hier soir en lien avec l’<a href="https://twitter.com/hashtag/attentat?src=hash">#attentat</a> de <a href="https://twitter.com/hashtag/Qu%C3%A9bec?src=hash">#Québec</a> est considéré comme suspect. —@sureteduquebec

Turcotte said the man parked about five kilometres from the scene of the shooting, near the bridge to Île d'Orléans, and waited for officers to arrest him.

"He was armed and spoke to us about his acts,'' said Turcotte.

'Pain and anger'

As Bissonnette's name began to circulate online, one Facebook group dedicated to welcoming refugees in the Quebec City area expressed "pain and anger" over the news.

The suspect was "unfortunately known to several activists in Quebec City for his pro-Le Pen and anti-feminist positions at Laval University and on social networks," wrote the Bienvenue aux réfugié.es - Ville de Québec Facebook group.

Bissonnette's Facebook page seemed to confirm those political leanings. The suspect followed several profiles that espouse right-wing ideologies, including that of Marine Le Pen, the far-right leader of France's National Front.

A search was conducted at the home of Bissonnette's parents on du Tracel Street in Cap-Rouge, as well as at a residence on des Quatre-Bourgeois Road, closer to the mosque.

A woman who identified herself as a neighbour of Bissonnette's parents said the suspect had recently moved into an apartment that he was renting with his twin brother, not far from the mosque where the shooting occurred.

"He is a child," she said. "You couldn't find one more calm than that. He never did anything, he always kept to himself. We never heard of anything."

"I saw him last Wednesday; he was arriving at his parents' home. I think he often went there," the neighbour, who wished to remain anonymous, told Radio-Canada.

Another neighbour, Réjean Bussiè​re, described Bissonnette as "a young man who is extremely withdrawn."

Bissonnette and his brother were not the kind to bother others, Bussiè​re said, "but they were not social people."

On social media, many took issue with the categorization of Bissonnette as an introvert and a lone wolf, arguing that the suspect was spared of the term terrorist because he is white. Bestselling author J.K. Rowling was one of those voices.

Earlier Monday, Prime Minister Justin Trudeau called the attack a "despicable act of terror."