Less than a week before the Democratic National Convention lands in Philadelphia, investigators made a worrisome discovery.

Officers approached a minivan in Germantown Tuesday evening, and discovered two improvised explosives and fireworks in the vehicle, CBS3 reported.

"The two improvised devices [had] the strength equivalent to about a quarter stick of dynamite, which is pretty powerful," Philadelphia Police Chief Inspector Scott Small told  CBS3. "So depending on how close those devices were to explode near people, they could cause serious injury, possibly even death."

Police approached the vehicle, which was double parked near 21st Street and Champlost Avenue, around 10 p.m., because of a strong smell of marijuana, 6ABC reported.

The 31-year-old driver had two three-year-old children in the car with him, police said. He was arrested and is facing charges relating to narcotics, explosives offensives and recklessness endangerment of children.

It's not clear what the driver planned to do with the explosives and fireworks. None of the explosives detonated.