California court bomber had arsenal in car: US government

LOS ANGELES - A California man who allegedly set off a small homemade bomb in a court had a small arsenal of weaponry in his car when he was arrested, the US government said.

Nathaniel McGuire was due in court on firearms charges when he allegedly threw a bag inside the building in Santa Maria, 250km northwest of Los Angeles on Wednesday.

Five people were hurt in the small blast that followed, as McGuire ran to his car, the Department of Justice said.

As he was tackled by law enforcement, "McGuire allegedly yelled that the government had taken his guns and that everyone needed to fight, rise up, and rebel," the DoJ said in a release.

"Inside the car, a deputy saw ammunition, a flare gun, and a box of fireworks. A search of the car revealed a shotgun, a rifle, more ammunition, a suspected bomb, and 10 Molotov cocktails."

Further bomb-making equipment was found at his home, the DoJ said.

A witness to the Wednesday incident told AFP the suspect had been "screaming that over 900,000 people a year are being killed" by the Food and Drug Administration, the branch of the US government that regulates medication.

The 20-year-old is charged with maliciously damaging a building by means of explosive, and could face up to 40 years in prison if convicted.

The United States is on heightened alert weeks ahead of a bitterly contested presidential election that has already featured a raft of conspiracy theories about supposed "deep state" plots to harm citizens.