BREWER – A makeshift bomb exploded in a Wilson Street parking lot Monday morning after a garbage truck driver discovered the device in the back of his truck.

No one was hurt as a result of the incident, which prompted a police investigation into the origin of the explosive, fashioned from an inert training model of a Claymore mine widely used in the Vietnam War. Unspecified explosives were added to the device, according to police.

The bomb exploded when an employee at Pine Tree Waste, formerly Sawyer Environmental Services, used a plastic shovel to throw it out of the truck and onto the vacant Pizza Hut parking lot.

“I threw it, shovel and all, and jumped into the cab,” Paul Barley, division manager at Pine Tree Waste, said after police cleared the scene “I probably shouldn’t have touched it, but I did what I did. I just wanted to get it away from everyone and everything.”

While the explosion – likened by Barley to a shotgun blast – caused no injuries, investigators believe the outcome could have been different.

“If this device worked like … we think it was supposed to work, someone could have been seriously injured or died,” said Brewer Police Department Cpl. Chris Martin. “The fact is we have someone making a bomb and placing it in our city … and we’d like to talk to them.”

Police on Monday were still determining whether the bomb’s maker simply meant to discard the modified device or target a specific business, Martin said.

Brewer police met with members of the Violent Crimes Task Force, a team of state and federal authorities including investigators from the Bureau of Alcohol, Tobacco and Firearms.

Martin said Monday afternoon that he was confident in the progress of the investigation, which could be aided by markings found on the device.

The otherwise harmless mine, used in military training exercises, can be purchased at some military supply outlets, said Martin, noting that the Wilson Street device had been stamped “inert.”

John Curtis, the truck’s driver, discovered the explosive in the back of his truck during the weekly collection of cardboard at businesses along Wilson Street. At the time of the discovery, Curtis was compacting the cardboard picked up at his first two stops, McDonald’s and Pizza Hut, when he noticed the wax-coated instructions to the device had blown out of the truck, Barley said.

Police believe the explosive was left in the cardboard-only bin behind the Wilson Street McDonald’s restaurant, which was evacuated to allow the Bangor Police Department’s bomb squad to search the building.

During that search, authorities, as a precaution, attempted to detonate an unidentified plain paper bag left on the floor. It was later discovered that the bag contained food.

Bomb squad personnel then turned their attention to a green canvas military bag found with the device. The open bag was found about a foot away from the explosive in the back of the truck, according to Barley, who had also removed the canvas bag with a long pole.

Bomb squad personnel also attempted to detonate that bag, believed to contain the device’s detonator. The bag did not contain any additional explosives, authorities said.

A live Claymore mine can cause significant damage, spraying a fan of shrapnel up to 170 feet, according to military manuals. Police would not comment on the specific contents of the device found Monday.

This is not the first time Pine Tree employees have picked up potentially dangerous items in the trash, Barley said. Used hypodermic needles and live shotgun shells are among the items that have put his crews in danger, he said, asking residents to use caution when discarding potentially hazardous material.