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 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, assault rifles and magazines and a large quantity of ammunition, the complaint said. They also found cellphones, computers and electronics equipment, including drone parts.

Bomb squad personnel called to the scene noted that the large amount of ammunition and electronic devices could be used for bomb-making, the complaint said.

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.

It could not be determined whether the FBI or another federal agency is investigating.

DAVID CHANEN