Man arrested in California had guns, explosives: Police

Howell was arrested around 5 a.m. after residents called police to report suspicious behaviour him

An Indiana man armed with three assault rifles and chemicals used to make explosives was arrested in Southern California and told police he was headed to a West Hollywood gay pride parade, an event that annually draws hundreds of thousands of people, authorities said.

The Sunday's arrest in Santa Monica of James Wesley Howell, 20, of Jeffersonville, came just a few hours after at least 50 people were shot and killed in a gay nightclub in Orlando, Florida, though police said they had found no evidence of a connection between the events.

The LA Pride event continued as usual, albeit with increased security. Los Angeles Mayor Eric Garcetti announced the arrest at the start of the parade and struck a defiant tone.

"We are here as Angelenos, as the LGBT community and allies," he said. "And we will not shrink away, we will not be stuck in our homes, we will not go back into our closets. We're here to march, to celebrate and to mourn."

Howell was arrested around 5 a.m. after residents called police to report suspicious behaviour by a man who parked his white Acura sedan facing the wrong way. When officers arrived they saw an assault rifle sitting in Howell's passenger seat, Santa Monica police Lt Saul Rodriguez said.

That prompted them to search the whole car. They found two more assault rifles, high-capacity magazines and ammunition and a five-gallon bucket with chemicals that could be used to make an explosive device, police said.

Santa Monica Police Chief Jacqueline Seabrooks initially tweeted that Howell told officers he wanted to "do harm" at the gay pride event, but she later corrected her statement to say only that Howell said he was going to the parade, about seven miles from the scene of the arrest.

Authorities would answer no further questions on Howell or his motives. The FBI is leading the investigation.

A Facebook page that apparently is Howell's includes photos of the white Acura he was driving in Santa Monica. The postings are unremarkable. There's no enmity toward gays or notable political activism. One post says he's signing a petition to legalise marijuana.

The page's most recent public post, from June 3, shows a photo comparing an Adolf Hitler quote to one from Hillary Clinton. An anti-Clinton, pro-Bernie Sanders photo was posted in February. The site said Howell worked as an auditor for a company that makes air filters.