A man armed with a folding knife who went on a random stabbing spree that left 11 people injured at a Michigan Walmart faces a charge of terrorism in connection with the attack, the authorities said on Sunday.

The man, Bradford James Gille, 42, of Afton, Mich., also faces 11 counts of assault with intent to murder, Sheriff Mike Shea of Grand Traverse County said at a news conference on Sunday.

Though officials said a motive for the attack remained undetermined, they are seeking to charge Mr. Gille with terrorism.

Such a charge is customary in a mass attack like the one on Saturday because its intent was believed to be to bring fear and destruction to a community as a whole, rather than to harm specific individuals, Noelle R. Moeggenberg, the prosecuting attorney for Grand Traverse County, said.

If convicted, the maximum penalty Mr. Gille would face for that charge would be life in prison, she said.

Mr. Gille used a “standard folding-style knife” with a 3.5-inch blade, Sheriff Shea said. He acted alone, the sheriff added.

Mr. Gille entered the store at 4:10 p.m. and remained there until the attack began around 4:45 p.m. at the store’s checkout area.

Mr. Gille was detained less than three minutes after the police arrived, Sheriff Shea said. He said that the attack appeared to be a random act.

The sheriff noted that “multiple citizens, including one who was armed with a pistol,” confronted Mr. Gille in the parking lot, “preventing him from harming further people and leaving.”

Sheriff Shea was unwilling to name the citizens or reveal additional information about them but he said, “What they did was amazing.”

Eleven people were initially treated for injuries at Munson Medical Center in Traverse City, said Megan Brown, the chief marketing and communications officer for Munson Healthcare, which runs the center.

As of Sunday afternoon, one victim had been discharged, two were in serious condition and the others were in fair condition, according to Dr. Tom Schermerhorn of Munson Healthcare. The victims, which included a Walmart employee, were between the ages of 29 and 84.

Mr. Gille was booked into the Grand Traverse County Correctional Facility. Ms. Moeggenberg said he would be arraigned this week. It was not immediately clear if he had a lawyer.

A shopper on Saturday described a scene of mayhem and confusion.

Julia Martell was in the canned vegetables aisle at Walmart when she heard screaming and saw a man with a knife running through the store’s pharmacy area, she said.

As the man moved through the store, he was shoving and stabbing people, she said. Then the man changed course and started running toward her.

She saw the knife in his hand — a knife with a blade about two inches long, she said — and ran. The man didn’t follow her and instead turned back toward the store entrance, she said.

“If anything, him not following me kind of scared me more because then you had no idea where he was,” she said.

Ms. Martell, 30, said she saw three people with stab wounds as she evacuated the store, including a man on the floor in the store’s frozen food section. There was “blood everywhere,” she said.

A spokesman for Walmart said the violence at its store was “unacceptable” and expressed gratitude for the quick response by emergency workers.

Hannah Ziegler, Rylee Kirk and Chris Loud contributed reporting. Susan C. Beachy contributed research.