Vancouver police took no chances after discovering two live hand grenades inside a cube van at a gas station.

Police were called to Fraser Street near King Edward shortly after 7 p.m. Thursday night for reports of a suspicious person in a gas station parking lot.

Officers arrived to find a 33-year-old man sitting inside a parked van outside of the convenience store at the Esso gas station.

A search of the vehicle turned up throwing knives, a tactical vest and two hand grenades.

The driver, who turned out to be a prohibited driver, was also found to have a set of brass knuckles in his pocket and a small amount of marijuana, according to the VPD.

The gas station was cordoned off by police tape as a bomb squad robot was brought in to analyze the explosives in the back of the truck. They used X-ray technology to find out if the grenades were active.

Closer examination revealed that not only were the grenades active, but they'd also been tampered with to make them more dangerous. Normally, there's a delay required to pull the pin of a grenade, but the pair had been altered so they could go off right away.

"Likely the driver was putting himself and his passenger at risk driving around with these things," Sgt. Brian Montague said.

The devices were taken to the school field at Sir Charles Tupper Secondary and exploded in a controlled detonation at around 3 a.m. Friday.

Residents said the detonations were loud enough to wake up many people in the neighbourhood.

"We heard a very big bang, not like a car accident or something," a woman named Veena said.

"Everyone in this area thought something was bombed."

Another said everyone was shaken up by the boom.

And it wasn't just loud. The force of the blast was strong enough to set off car alarms in the neighbourhood, and left a footprint of about 15 metres in the school yard.

The Surrey man in the truck was taken into custody and the force says it is pursuing multiple charges against him. The VPD said Friday the suspect has a minor criminal record, but has no known ties to local gangs.

Asked whether the explosives were part of a plan to harm the public, police said they did not have more details, "but we'll ask."

With reports from CTV Vancouver's Sheila Scott and Penny Daflos