A Donald Trump supporter was arrested after police detonated an explosive device they believe he planned to use against Muslims.
Police received a tip Thursday that 55-year-old William Celli, of Richmond, California, was making explosive devices and threatening to harm Muslims, reported KPIX-TV.
Officers evacuated his neighborhood Sunday morning and detonated a suspicious device found in Celli's home.
Police have not yet determined if the homemade device was inert or active, but they said the reported threats greatly concerned law enforcement officers.
Celli posts frequently on his Facebook account, where he complains about Syrian refugees, Democrats and insufficiently conservative Republicans.
He appears to be a strong admirer of GOP frontrunner Donald Trump -- who has been fanning the flames of anti-Muslim hysteria in the wake of mass shootings in Paris and San Bernardino, California.
"Donald trumps on again I'm happy leaders okay but this guys a great point man I'll follow this MAN to the end of the world," Celli posted Oct. 21.
"Donald Trump's on again I'm feeling good about myself," he posted Oct. 28.
The self-employed plumber complained last year that he had lost work to undocumented migrants -- who he believes have "invaded" the U.S. and to draw welfare benefits.
"I have lost 30%of my business to to Hispanics coming to my country under false pretenses an and freeload in construction or in the blue collar sector they need to go back home lets not talk about the welfare they suck dry," he posted in June 2014.
Celli posted more recently that he had more free time than usual, and he frequently complained that he had not been sleeping well.
Two brothers from Boston echoed Trump's comments against Hispanic immigrants after they were arrested for beating and urinating on a Latino homeless man in August -- and the candidate at first defended them.
“I will say that people who are following me are very passionate,” Trump said. “They love this country and they want this country to be great again. They are passionate.”
Trump later described the attack as "terrible."
Watch this video report posted online by KPIX-TV: