Dec. 4 (UPI) -- The FBI has arrested a suspect in the Jan. 6, 2021, pipe bombing attempts at the Democratic and Republican national committee headquarters, sources have said.

But an arrest was made Thursday morning, CNN, CBS News and NBC News reported. No details have been released from the FBI, but there will be a press conference Thursday to announce the arrest, an FBI official has told NBC News.

The case has baffled law enforcement for nearly five years, as the grainy surveillance video didn't leave many clues. The suspect allegedly placed pipe bombs outside the RNC and DNC headquarters on the evening of Jan. 5, 2021 -- one day before the Jan. 6 Capitol riot.

The pipe bombs were made of 1-inch galvanized pipes, 8 inches long with end caps, homemade black powder, wires, metal clips and a kitchen timer. The FBI has said that the bombs were viable and could have seriously hurt people nearby if they had exploded. It has offered a $500,000 reward for information on the suspect. The bombs sat for 15 hours before being discovered.

Related