MUSKOGEE, Oklahoma - A convicted felon, arrested last Friday at a Tahlequah hospital after a homemade bomb exploded in his hand, now faces a new federal charge.

Jeremy Ramirez, 27, was charged Wednesday with felon in possession of an explosive, the U.S. Attorney's Office says.

Police were called after Ramirez showed up at a Tahlequah emergency room with apparent shrapnel wounds.

ATF Assistant Special Agent In Charge Paul Vanderplow said Ramirez was attempting to wire his cell phone to a blasting cap.

"[It] went off in his hand and caused some pretty significant damage to his hand and some of his extremities," Vanderplow said.

Ramirez was discharged from the Oklahoma Department of Corrections in September, 2012, after serving time for possession of drugs, possession of a stolen vehicle and feloniously pointing a firearm.

Those offenses took place in Tulsa and Adair counties.

Investigators said Monday they don't know yet what kind of intent Ramirez may have had.

"[There are] a couple different scenarios we're working on. We don't have all the information put together yet. We're still working on that for further investigative leads to follow up on that," Vanderplow said.