Washington DC - The Virginia man accused of planting pipe bombs near the Democratic and Republican Party headquarters on the eve of the January 6, 2021 Capitol attack made his first court appearance on Friday.

Brian Cole Jr. of Woodbridge, Virginia, did not enter a plea at the hearing in district court in Washington DC.

Magistrate Judge Moxila Upadhyaya ordered Cole, who was arrested at his home on Thursday, to remain in custody until a detention hearing on December 12.

Cole has been charged with interstate transportation of an explosive device and attempted destruction using explosive materials.

The 30-year-old's arrest was the first breakthrough in a nearly five-year-old case that spawned numerous conspiracy theories among the far right.

Attorney General Pam Bondi, at a Thursday press conference, declined to speculate on whether the pipe-bombing was politically motivated, saying the investigation was ongoing.

CNN and NBC News reported on Friday that Cole had told the FBI in interviews since his arrest that he believed the 2020 presidential election was "stolen" from current President Donald Trump.

Ex-President Joe Biden won the 2020 vote, but Trump continues to falsely claim that he was the rightful winner.

The pipe bombs – placed outside the Democratic National Committee and Republican National Committee offices in Washington on the evening of January 5 – failed to detonate.

The devices were discovered by authorities the next day as Trump supporters stormed the Capitol in a bid to prevent congressional certification of Biden's election victory.

The FBI released many photos and video clips of a masked and hooded suspect over the years and eventually increased the reward for information leading to an arrest to half a million dollars.

After taking office for a second time in January, Trump pardoned more than 1,500 people charged or convicted of taking part in the assault on the Capitol.