Residents of a quiet Kamloops, B.C., neighbourhood are reeling after an armed man strapped explosives to himself and his van and barged into his ex-girlfriend's home, which exploded into flames after four children escaped.

Vern Reynolds, 79, said he heard a shot and saw 12 or 13 police cars with lights flashing outside a house where the suspect is presumed to have died after releasing the woman he'd held hostage for nearly seven hours.

"Shocking, shocking, shocking. That's what it is," Reynolds said Friday. "There is just disbelief, disbelief."

Simon Harry said the children took refuge in his home in the same cul-de-sac.

"I couldn't believe something like that was actually happening," Harry said. "My daughter was just in the house a half hour before it went down. I'm still trying to process everything."

RCMP Staff Sgt. Grant Learned said investigators couldn't get into the house Friday because the site was still too hot. They had planned to begin sifting through the rubble for the 48-year-old man's remains and evidence of the blasts that rocked the neighbourhood.

He praised the heroics of police and firefighters who worked in a dangerous and surreal situation that could have been much worse.

Bomb technicians risked their lives to prevent a pipe bomb from exploding and causing fatalities in the immediate area, an emotional Learned told a news conference.

He said they also grabbed a propane tank and a gas cylinder from the approaching fire as flames ripped through the roof of the house.

Learned said the suspect took his former girlfriend hostage as three children were whisked out of the home by another man. A fourth child fled through a bedroom window.

"Negotiators learned that the man was still distraught over the breakup with his former girlfriend two years earlier," Learned said, adding he doesn't know if the man is the father of the children, aged eight to 13.

He said the 44-year-old woman had twice called police after the suspect began leaving gifts outside her door.

"No one would have ever foreseen the results of last night, why someone would go to that extreme," he said.

"The emotional scars for the children, and the lady, will be long and deep. They've lost their home, they've lost everything. And there was a person who was, for a period of time, in their lives who also has been taken from them."

Learned said the suspect had contact with police in other areas for matters involving "emotional distress and emotional well-being."

Police evacuated 15 homes and contacted the suspect inside the home shortly as the drama unfolded, just after 5 p.m. Thursday, Learned said.

"The man told police that he had explosives wired to his body, that explosives were in the residence, that an explosive device was wired to the gas tank of his vehicle and that there was a second bomb in the (van)," he said.

"The suspect, who is an electrician by trade, provided specific details to the negotiator regarding how the explosives were wired and how he would be able to detonate the devices remotely."

The woman was released unharmed at midnight as the suspect continued speaking with a negotiator, but the phone line went silent about 10 minutes later, Learned said.

"Officers on the scene heard two rapid explosions erupt from within the house and a smoke detector alarm was set off," he said, adding flames began to spread.

However, fire crews stationed close to the home had to be kept at a safe distance because of the suspected bomb in the man's vehicle, Learned said.

After a third explosion from inside the house rattled neighbouring homes, RCMP bomb squad experts approached the van to assess the threat of explosives the man mentioned, he said.

"Through the windows of the vehicle they could see a series of wires leading from a switch attached to the driver's door and one set of wires attached to a metal pipe bomb on the vehicle console."

"In the back, they could see a five-gallon gas can and a 20-pound propane cylinder. The pipe bomb could not be safely neutralized in the vehicle, which was parked meters away from the burning home."

The risk of another explosion and flammable material inside the van meant firefighters had to fight the house fire from 100 meters away to keep it from spreading to other homes while dousing water on the vehicle to keep it cool, Learned said.

"Once the scene was stabilized, the bomb squad officers used a robot to safely remove and neutralize the explosive device," Learned said.

A second bomb attached underneath the vehicle was removed Friday morning.

"It's terribly sad," said neighbour Fred Bartlett.

"There are some really nice little children involved here and we often played with them on the cul-de-sac and one little boy (who) lives with us played with them often and this just ends horribly for everyone."