WATERVILLE — Federal agents who searched a Waterville apartment last week arrested an 18-year-old man living there after finding “handmade explosive devices,” according to a federal criminal complaint.

FBI agents found three explosive devices that investigators determined were fireworks bundled together with tape. An FBI bomb technician who examined the devices found staples, pins and thumbtacks attached to them that the technician believed were meant to be “shrapnel” when the devices were detonated, the complaint said.

FBI spokeswoman Kristen Setera said this week that Xavier Pelkey was taken into custody “without incident.” She declined further comment, citing an ongoing investigation.

Pelkey is facing a federal charge of possessing unregistered destructive devices.

Pelkey told agents who raided his apartment Friday at 80 Front St. that he taped the fireworks together because he wanted to make a “bigger boom,” according to the complaint. He did not respond to questions about why staples and other sharp items were added to the fireworks, the document said.

The complaint, obtained this week, did not say why the devices were made or what the intention was for them. It said a search warrant was obtained for Pelkey’s apartment for “firearms, explosives and explosive components.”

The FBI determined that the material seized Friday met the definition of “destructive devices” under federal law and the metal objects show that the device was designed to be used as a weapon, the complaint said. It also said that Pelkey does not have any “destructive devices” registered with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, making those in his possession illegal.

Pelkey has a preliminary hearing scheduled for Wednesday in U.S. District Court in Portland. Court records indicate Pelkey is being held at the Somerset County Jail, but an employee who answered the phone Tuesday would not confirm he’s incarcerated there, making the false claim that it’s “privileged information.”

The prosecutor assigned to the case is Assistant U.S. Attorney Craig Wolff. Pelkey is being represented by Camden lawyer Christopher MacLean. Neither attorney could be reached for comment Tuesday.