Updated

A shoplifting arrest turned into a bomb scare at an Indianapolis gas station when police found explosives materials similar to those used in the Columbine High School massacre.

Indianapolis Metropolitan Police Department officers found CO2 cartridges, about a pound of gunpowder and a gas can rigged with gunpowder Monday after stopping two men on suspicion of shoplifting a local Target, Lt. Jeff Duhamell told FOXNews.com.

"What concerns me is the CO2 canisters, if in fact they were going to make cricket-type explosives, which is just a miniature pipe-bomb-type deal," Duhamell said.

Those empty canisters can be filled with gunpowder to make the "cricket" explosives used by Eric Harris and Dylan Klebold in the 1999 Columbine attack that left 13 dead.

Gregory Killion, 22, and Daniel Filskov, 18, were arrested on charges of possession of destructive devices and theft when police pulled them over at a Shell Station after receiving a shoplifting call from a Target store.

As they removed Nintendo games and a Wii from the backseat of the suspects' Pontiac, the officers noticed "a plastic bottle shoved under the handle of a gas can that contained a black powdery-like substance," according to the police report.

Thinking they had found narcotics, the officers opened the bottle and discovered incense and a paper towel as well as gunpowder, the report said.

"At this time, we believed we had a homemade pipe bomb and we exited the vehicle and took both of the suspects to a safe location," police wrote in the report.

Bomb crews were called in to handle the explosives.

Killion was arrested last month on a domestic violence charge, Duhamell said. Filskov does not have a criminal history.

Killion was also charged with resisting arrest and battery with injury toward an officer after allegedly telling police he would "beat himself up and blame us for it," according to the report. Killion allegedly struck his head against the side of the police car and kicked out a door, injuring an officer.

An investigation is under way as to how the pair planned to use the explosives. Filskov told police he was "trying to make a firework with the gunpowder," officers wrote.

"I don’t think these kids are in school or anything of that nature," Duhamell said. "Ever since 9/11, we’re more attuned to check things of this nature out and be thorough."