A 22-year-old Winnipeg man says he is happy to be alive and praying for his injured friends after a bomb exploded in the pickup truck they were in on the weekend.

"Just want to know who it is who would be doing something like this," a bandaged-up Shaunovin Houle, one of four people who sustained major injuries during the explosion on Saturday, said outside Health Sciences Centre in Winnipeg. 

"If it wasn't us it would've been someone else."

Police reported Tuesday morning that two people — a 27-year-old man and 20-year-old woman — were in critical condition after the explosion. Houle said Tuesday afternoon his two friends are now responsive and in stable condition.

Houle and a 17-year-old boy who were also in the vehicle were treated for serious injuries, including severe burns. Houle's face was burned, and his entire left arm and right hand remain covered in gauze.

The explosion happened around 11:15 p.m. CT Saturday in the city's Brooklands neighbourhood. Immediately afterward, the truck hit a fire hydrant at the intersection of Gallagher Avenue West and Midmar Avenue.

'Curiosity can get you killed': Victim of Winnipeg bomb explosion happy to be alive2:17

The improvised explosive device was in a bag inside the cab of the truck when it accidentally went off, Winnipeg Police Service spokesperson Const. Rob Carver said Tuesday.

"The four victims who were injured were not intended victims," he said.

Carver said he was unable to provide specific answers because of the continuing investigation. He noted, however, the bag was brought to a 7–Eleven parking lot at Gallagher and Keewatin Street by someone not connected to the four people who were in the truck.

'All of them are saying it was a flash before their eyes, because they all thought they were going to die.' - Nick Chastellain

That person left the bag to go inside the store. It was then picked up by someone from the truck, he said.

Nick Chastellaine, whose 20-year-old girlfriend was the one who took the bag, told CBC she intended to turn it over to police.

Chastellaine wasn't in the truck, but his girlfriend, cousin and friend were three of the four occupants. He said he spoke to them afterward, and they told him they opened the bag to see if there was anything inside to identify the owner.

That's when the bag burst into flames, he said.

Shaunovin Houle, 22, injured in Winnipeg explosion

Shaunovin Houle, 22, sustained burns to his face, arms and upper body after a bomb exploded inside a truck he and three others were riding in over the weekend. (CBC)

"The whole truck, inside the cab, just ignited into flames within like seconds," he said. "All of them are saying it was a flash before their eyes, because they all thought they were going to die."

Houle was sitting in the back seat behind the 20-year-old woman when the bomb exploded. His friend who was driving the vehicle first noticed the bag and instructed the woman to pick it up, Houle said.

"As soon as she stuck her hand in the bag it just engulfed in flames," Houle said. "Curiosity can get you killed."

Not intended victims: police

The person who brought the bag to the 7–Eleven was also not an intended victim and might not have known what was inside, Carver said. He wouldn't elaborate further on what police know about the bomb or its intended target.

"We have some sense of that, but it's not something we can release on at this point," he said. "There are just elements I cannot speak on at this point."

The truck had only driven about 50 metres from the 7–Eleven when the bomb detonated.

Initially, emergency crews responded to what was believed to be a crash that caused the truck to go up in flames. The four people were found outside the vehicle suffering from severe burns.

"It's just luck that they [victims] weren't more seriously injured," said Carver. "We've got video of the truck on fire. It's a horrific scene and I can tell you the Winnipeg Police Service has devoted all of the resources that we can to tying this up."

'Incredibly alarming'

It is "incredibly alarming" that an IED was out there and injured four people, he said.

Burn marks remain near a fire hydrant in the 1st block of Gallagher Avenue.

Burn marks remain near a fire hydrant on Gallagher Avenue West. (Travis Golby/CBC)

"It's obvious that it was designed for maximum effect, to create what it did in that vehicle. Was it designed to do that with an intended victim? I simply don't have that information at this point," Carver said.

"It's reasonable to assume that when someone has gone to all the trouble to make an explosive device of this power, that there's some back story. But I don't have the luxury of being able to share it at this point."

He apologized for being vague about what happened, saying he is struggling to balance the needs of transparency with the need to maintain the integrity of this investigation.

"I know it's confusing … but that's the best we can do at this point," Carver said. "I have spent an inordinate amount of time trying to understand the nuances of this particular case as well."

'A really uneasy feeling'

Police do not feel there is any continued threat to the public.

"We are not looking for any other devices," he said. "We do not believe that someone has randomly put an explosive device out in the public with the intention that innocent victims could be injured."

Shaunovin Houle, injured in Winnipeg explosion

Houle holds up his burned armed outside the Health Sciences Centre in Winnipeg Tuesday. (CBC)

Meanwhile, Houle said he wonders what could have happened if someone else had picked up the bag.

"Especially knowing if we weren't the ones, it is somebody else who would've found that bag," Houle said. "It's a really uneasy feeling."

Anyone with information that may assist investigators is asked to call 204-986-6219 or Crime Stoppers at 204-786-TIPS (8477).

With files from Nelly Gonzalez