(CNN) -- A British Columbia man who held authorities at bay for more than six hours after allegedly strapping explosives to his body is presumed dead after the house he was holed up in exploded, Royal Canadian Mounted Police said Friday.
The 48-year-old man, who was not immediately identified, is accused of storming his ex-girlfriend's home in the town of Kamloops, northeast of Vancouver, and taking her hostage, according to an incident report released by authorities.
The man told police he had explosives strapped to his body and to the gas tank of his van.
"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 report said.
The incident began Thursday night when the man forced his way into the house and fired a shot into the ceiling, ordering the woman's four children and her new boyfriend out of the house, the report said. He then held the woman hostage at gunpoint, it said.
"Negotiators learned that the man was still distraught over the break-up with his former girlfriend two years earlier," the report said.
Authorities evacuated 15 houses in the neighborhood, police said.
Shortly after midnight, hostage negotiators persuaded the man to release his ex-girlfriend, whose identity was not released.
"The man continued to speak with the negotiator. But 10 minutes after the woman had been released, the telephone line went silent," the report said.
"Officers on the scene heard two rapid explosions erupt from within the house and a smoke detector alarm was set off."
A third, larger explosion followed, rattling houses in the neighborhood, police said.
While firefighters attempted to battle the house fire, members of the bomb squad found another bomb in the man's van.
"In the back, they could see a 5-gallon gas can and a 20 lb. propane cylinder," police said.
Once firefighters got the fire under control, the bomb squad used a small, remote-controlled robot to "neutralize" the bomb, the report said.
"Investigators will start the arduous task of sifting through the rubble looking for the remains of the suspect and other evidence related to the explosions from within the house," the report said.
Neighbor Vern Reynolds, 79, told CNN affiliate CTV the first indication there was something wrong at the house was the sound of a gunshot. That was followed by the arrival of more than a dozen police cars.
"Shocking, shocking, shocking. That's what it is," Reynolds said Friday afternoon. "This is just disbelief, disbelief."
Another neighbor Simon Harry said the four children took refuge in his home in the cul-de-sac while authorities negotiated for their mother's release.
"I just can't believe something like that was actually happening," he told CTV.
CNN's Jake Carpenter contributed to this report.