TOPEKA, Kan. (AP) – Police say they’ve arrested the owner of a suspicious pickup truck that was found parked near the Kansas Statehouse with several homemade explosives inside. Authorities said the truck had specialty license plates issued only to U.S. military paratroopers.

Capitol Police Spokesman Patrick Saleh  says officers arrested the pickup’s owner Wednesday in an underground tunnel that connects the Statehouse to a nearby state office building.

Saleh also says the incident isn’t connected to another arrest Wednesday of a man who allegedly phoned in a threat to Governor Sam Brownback’s office from a Topeka motel.

Saleh said the Topeka Police Department’s bomb squad was called to investigate the pickup after an officer saw suspicious objects inside. He says they found explosives made with household materials and designed to spray shrapnel upon detonation.