BARRIE, Ont. -- Police in Barrie, Ont., say they've discovered 72 explosive devices so far in a search of a home where two men were arrested last week in a 1978 homicide.

About 60 neighbours were evacuated from nearby residences last Thursday after police found explosives and unknown chemicals in the home. The residents are expected to be out of their homes for the rest of this week.

Investigators released photographs Tuesday of some of the devices and weapons found in the home and underground bunkers on the property.

The city of Barrie approved a permit in 1984 to the owner of the home for a fallout shelter which police photos show crammed with boxes and jugs of liquid.

Building services manager Gord Allison says the central Ontario city has had the occasional request for such structures but it's rare.

Donald Feldhoff, 54, was charged with first-degree murder after turning himself in to police last week. His 75-year-old father William has been charged as an accessory after the fact.

The father and son are charged in connection with the slaying of 26-year-old Michael Traynor.

The investigation into Traynor's death went cold shortly after his body was found in a wooded area in October 1978.

Police said he had been bound and shot multiple times in the chest.

In addition to the improvised explosive devices and various rifles and shotguns, police say they have found numerous rounds of ammunition.