Minneapolis police uncovered an arsenal of guns and bomb-making devices during a routine arrest last week.

According to police, a man walked by a parked car in north Minneapolis about 5 p.m. Thursday and confronted the people inside after they threw food wrappers on the ground. They ignored him until he paused to get the car license number. The men then got out of the car and indicated they had guns, according to a criminal complaint filed Monday.

The man flagged down officers, the complaint says, but the men from inside the car continued to yell at him and resisted the officers’ attempts to control the situation. The men were insistent they needed to be near the car because a drone was coming to deliver a package, the complaint said. Because of the suspicious circumstances and fear for the man’s safety, the men were placed in the squad while officers searched their car.

Inside, the officers found a hand grenade, handgun, rifles, magazines and a large quantity of ammunition, the complaint said. They also found cellphones, computers and electronics equipment, including drone parts.

Abdullah N. Alrifahe, 27, of Minneapolis, was charged with a gross misdemeanor for carrying a pistol in public without a permit. In December, he was convicted of the same offense, the Minneapolis Star-Tribune reports.

Other charges could result from further investigation.