Philadelphia police say they've found two explosive devices inside a van with young children in it.

Police made the discovery after spotting a minivan that was double-parked in the city's East Germantown neighborhood Tuesday night.

Officers say they smelled marijuana and found drugs, fireworks and two explosive devices. Two 3-year-old children were also in the van. Homes in the area were evacuated.

Police arrested the 31-year-old old driver. They did not immediately release his name. Officials say the bomb squad confiscated homemade explosive devices that are the equivalent of two quarter sticks of dynamite.

Police say the timing of the incident is concerning as the Democratic National Convention is set to take place in Philadelphia next week.