A suspect has been captured three hours after a stabbing attack at a grocery warehouse in northwest Edmonton that killed two people and wounded four others.

"A very vigilant citizen noticed the vehicle with somebody matching the description of the suspect inside it," said Edmonton police acting Insp. Malcolm Allan. "Our tactical team just now took the individual into custody and confirmed that it is the same person.”

The suspect, Jayme Pasieka, 29, surrendered peacefully in a takedown at 74th Avenue and 39th Street in southeast Edmonton.

The attack happened just after 2 p.m. MT at the Loblaw's Western Grocers warehouse at 16104 121A Ave., which handles food for the region's Superstores.

Police believe all the victims were employees.

Of the surviving victims, one is in grave condition, while a second is in serious condition. The remaining two have non-life-threatening injuries.

"It’s alleged that he went on a bit of a rampage inside there,” Allan said.

The victims were found throughout the warehouse, which is the size of two football fields with a 10-metre ceiling. More than 100 people work at the warehouse.

'A lot of traumatized people'

“There’s a lot of traumatized people. So we have our victim services people, a full-court press, in that regard," Allan said. "We’re trying to help these individuals as best we can.”

When workers were finally allowed to leave, many were visibly shaken.

"His car was parked right beside mine," one man said of his encounter with the assailant. "He said, `You want to get stabbed?'"

The man paused, his voice began to crack and then he drove away, telling reporters: "Sorry, guys, can't take it, gotta go."

Aaron Nganatafam, who had been inside the warehouse, said he knew the attacker and considered him "very weird. No friends, nothing ... It was like in the movies, really."

Police said Pasieka was employed at the warehouse, but they don't know if he was on shift at the time of the attacks.

"He was armed with two knives and was wearing body armour during this incident," Allan said.

One witness reported seeing the suspect, dressed in military garb, fleeing the scene.

Suspect had previous conviction

Allen said a motive for the attack isn't yet known but noted the weapons and body armour "suggests there may have been some pre-planning," he said.​

Pasieka was convicted of threatening to cause death or bodily harm and assault with a weapon over an incident in May 2009. He was sentenced two years later to 15 months probation.

In that incident Pasieka threw eggs at his neighbour's truck, set a heart-shaped fire on their street and brandished a compound bow and arrow.

Pasieka told police he did it in the name of the Queen. His father told court he had suffered a head injury three years earlier and since then takes a little longer to understand things.

Loblaw would not comment on the attack.

“We are sad to confirm that there has been an incident at our Edmonton distribution centre," said spokesman Kevin Groh in a release. "Our full attention is on the health and well-being of our colleagues."