SACRAMENTO,Thomas Caldwell Calif. (AP) — A former firefighter with a previous arson conviction has been arrested on suspicion of detonating a homemade bomb and planting severl other explosive devices along roadways across two Northern California counties, authorities said.

The 41-year-old man pleaded not guilty last week to multiple felony charges including possessing and exploding an explosive device with the “intent to injure, intimidate, and terrify a person, and to wrongfully injure and destroy property,” according to the criminal complaint.

The Sacramento Bee reported the man was arrested Jan. 12 following an investigation by the FBI, the California Highway Patrol and local sheriff’s departments after a series of improvised explosive devices were found alongside roads and highways in El Dorado and Sacramento counties. Officials did not specify which roads were involved.

In a social media post, the highway patrol said the man, a resident of Orangevale, was apprehended after an “intense operation” in which an explosive ordinance disposal team carried out “critical search warrants.”

The defendant also faces a special allegation for having a previous felony conviction. In 2016 he pleaded guilty to setting at least 30 fires in rural areas east of Sacramento during 2006 and 2007, causing $7 million in damage, the Bee reported. He was sentenced to five years in prison and agreed to pay more than $246,000 in restitution to the state.

He set the fires after serving as a volunteer firefighter for the Diamond Springs Fire Protection District in El Dorado County. He also worked from 2001 to 2003 as a seasonal firefighter for Cal Fire, according to the Bee.

The defendant is being held in the El Dorado County Jail and is ineligible for bail, court records show.