Police in Barrie, Ont., started using a small bomb-like device to neutralize explosive material found at a north-end home, which prompted a neighbourhood evacuation on Thursday.

Several explosive devices, containers of chemicals and a number of firearms were found at the Barrie home after a break in a 30-year-old murder investigation led to two arrests and a search of the Barrie home.

Staff Sgt. Norm Meech said five explosive devices and numerous bottles of unknown chemicals were discovers inside and around the base of the residence at 30 Virgilwood Crescent, north of the city’s downtown core.

The age and disrepair of the devices has made the scene very unstable, Meech said, and bomb disposal units were moving slowly to neutralize each threat.

“This is a very complex, slow time-consuming process to safely handle these devices, and to fully understand that some of these devices may have been in this house or outside of this house for the past 20 years,” Meech told reporters on Friday.

“We are proceeding very slowly. There are some wires exposed. We have not found a booby trap yet, but there are wires around; we don’t know.”

Meech said a bunker about seven feet deep was found near the home, and a second bunker is believed to have been built under the back deck. He said the explosive devices around the area have limited the scope of the police investigation.

Friday morning Barrie police said they planned to use a “disruptor” later on Friday to neutralize some of the explosive devices. Meech said the disruptor is a small explosion that renders some forms of explosives safe to handle.

He said police would issue a warning before the device – which sounds like a gunshot – is expected to be used.

By Friday afternoon, police began disabling some of the homemade explosives.

Plumes of smoke could be seen rising into the sky.

But Meech told the Canadian Press that dangers remained, even after some of the devices had been disabled.

"We have to now deal with unknown chemicals in various containers inside the residence," he said. "After our explosive disposal unit deems it's safe, then we have to begin our criminal investigation into the firearms as well as the making of these explosive devices."

Once the residence is safe, Barrie police will begin an investigation into the possession of explosive and into several firearms located at the residence. Criminal charges related to the explosives and firearms are expected to be laid next week.

Barrie and Provincial Police units evacuated 22 homes and 57 residences on Thursday after an investigation into a cold case homicide led them to the residence.

OPP Insp. Martin Graham said a break in the investigation into the murder of Michael Traynor led to the discovery.

The 26-year-old Barrie resident was reported missing by his family on Sept. 18, 1978. His body was found suffering obvious signs of trauma several weeks later.

Graham said Donald Feldhoff, 54, turned himself into police on July 11. He has been charged with first-degree murder and will appear in a Barrie court next week.

His father, 75-year-old William Feldhoff, has been charged with being an accessory to murder after the fact and will also appear in court next week.

Graham said that the explosive devices were not connected to the homicide, but police learned of their existence through the investigation.

“Both the accused, prior to their arrest, had resided in the residence behind us,” Graham said from the scene on Friday.

Families evacuated from the area are expected to remain displaced through Friday.

With files from The Canadian Press