Michigan authorities said Sunday they are seeking to file terrorism charges and 11 charges of assault with intent to murder against a 42-year-old man accused of carrying out a knife attack at a Walmart store.

According to the Grand Traverse County Sheriff Michael Shea, a 42-year-old man — identified as Bradford James Gille, of Afton, Michigan — used a folding knife with a 3.5-inch blade to stab five men and six women, including one Walmart employee, on Saturday afternoon. The ages of the people injured range from 21 to 84.

Law enforcement was notified of the attack around 4:43 p.m., Shea said, and a sheriff’s deputy was at the store around two minutes later.

“At the time of the deputy’s arrival, multiple citizens, including one who was armed with a pistol, were confronting the male suspect in the parking lot and preventing him from harming further people and leaving,” the sheriff said. “The deputy took the suspect into custody without further incident.”

Gille is currently held at Grand Traverse County Jail, where he will remain pending formal charges and arraignment, which is expected to be Monday or Tuesday, officials said.

Authorities are working to find out the motive behind the attack.

“As far as a motive, that’s yet to be determined,” Shea said on Sunday. “Our detectives, with assistance from the FBI, interviewed him at length, and that will be part of the investigation as it moves forward.”

“Violence like this is unacceptable,” Joe Pennington, a Walmart spokesperson, told CBS News in a statement on Saturday. “Our thoughts are with those who were injured and we’re thankful for the swift action of first responders.”

Conditions of the wounded improving

The conditions of the 11 people who were stabbed at a Walmart in Traverse City, Michigan, are improving, medical officials said Sunday afternoon.

As of 2 p.m., two people are in serious condition, eight are in fair condition and one has since been released from the hospital, according to Munson Healthcare. On Saturday night, five were in serious condition and six were critical. 

Dr. Tom Schirmerhorn, chief medical officer of Munson Medical Center, said everyone is expected to survive.

“Over the past 12 hours, we’ve seen encouraging signs of recovery from our patients,” the northern Michigan-based company said in a written statement Sunday morning. “Our dedicated team of physicians, surgeons, nurses, clinicians, and support staff remain focused on providing a healing environment for all those affected by this tragic incident.”

The company added that it’s working to provide emotional support for Walmart employees impacted by the attack.