Police charged 18-year-old Vladislav Miftakhov of Altoona with possessing a weapon of mass destruction, risking a catastrophe and other counts.
It's not clear if Miftakhov has a lawyer. He's being held at the Blair County prison.
Police say they were investigating a reported marijuana growing operation at Miftakhov's address on Friday when they found and dismantled the suspected bomb. They also allegedly found a suitcase containing explosives-related material. Police say Miftakhov told them he purchased the equipment online over the past few weeks.
Andrew Leff tells the Altoona Mirror that he warned Vladislav Miftakhov to get rid of the bomb-making materials. He called Miftakhov "dumb" and "crazy," but not dangerous.
WJAC-TV reports the suspect is a Russian citizen. The Altoona Mirror says Miftakhov is an engineering major at Penn State-Altoona.
"I never thought he would take it to such extremes like this that he'd be facing charges for weapons of mass destruction," Leff told reporters in Altoona.
"He's the weirdest human being I've ever met, to be honest. He always doing abstract things but never really anything dangerous like this before."
Leff added, "He'll just come over to my side of the apartment, take food out of the kitchen without us even giving him permission. He'll say some bizarre stuff really."
A woman who lives in the neighborhood also told reporters she once accidentally received a package intended fro Miftakhov.
"But when I saw the name I remembered getting one of his packages here and then returning it to him that was a couple of months ago wondering what was in that package now,... a little bit," Chelsea Garcia Ortega said.
Altoona police and federal agencies say more information abohut Miftakhov's arrest will come Monday.
Information from the Associated Press and CNN was used for this report.