A Colorado man who lived near a park crafted explosives he claimed could kill everyone within 20 meters, hoping to trade the bombs and other weapons for cocaine or cash, authorities said.

Special agents with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives arrested Richard Sandberg, 35, on Thursday morning as he was heading to work, said Jeffrey Dorschner, a spokesman for the U.S. Attorney's Office in Colorado.

In the afternoon, he appeared in federal court, where he was ordered held without bond until at least a detention hearing Tuesday.

His arrest followed an undercover sting that revealed the suspect had an arsenal of "homemade" improvised explosive devices and military-grade grenades in his suburban Denver home, according to an affidavit filed by an ATF agent in federal court.