Mayor Eric Garcetti said it is believed the man is completely unrelated to the Orlando massacre

Tannerite, an ingredient used to make pipe bombs, was also discovered

Three rifles and a substantial amount of ammunition was found in his car

Discovery came just hours after 49 were killed in worst mass shooting in US history at Orlando gay club

James Wesley Howell, 20, told Santa Monica police he 'wanted to harm' people at the Los Angeles Pride festival this weekend

An Indiana man who was found with an arsenal of assault rifles, ammunition and explosives in his car told police he 'wanted to harm' people at the Los Angeles Pride festival.

James Wesley Howell, 20, was arrested in Santa Monica after concerned residents called police around 5am to say he was loitering around and knocking on people's doors.

When investigators searched his vehicle, they found three rifles, a substantial amount of ammunition and 5lb of mixed Tannerite powder, which can be used to make a pipe bomb.

Also inside the white Acura were assault rifle magazines taped together, to allow for quicker reloading, a camouflage outfit and a security badge.

Police say Howell admitted he was on the way to the LA Pride event to meet a friend, and 'wanted to harm' people there.

Howell's arrest came on the same morning the country was rocked with the worst mass shooting in US history, at a gay club in Orlando where 49 people were shot dead..

Mayor Eric Garcetti earlier said it is believed the man is completely unrelated to the Orlando massacre.

Seabrooks said officers are still trying to establish Howell's motives, according to the Los Angeles Times.

The investigation has since been taken over by the FBI.

Authorities are currently looking for the friend the suspect said he planned to meet at the parade. Howell is being held on $500,000 bond at the Santa Monica Jail.

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Police inspect a car in Santa Monica where an 'arsenal' of assault rifles, ammunition and possible explosives were discovered inside

A car inspection revealed three rifles, a substantial amount of ammunition and 5lb of mixed tannerite, an ingredient that can be used to make a pipe bomb, as well as a camouflage outfit

Officers confronted Howell after neighbors reported that he was knocking on doors and 'loitering in the area' around 5am, according to Santa Monica Police spokesman Saul Rodriguez

Howell is also currently serving a one-year probation term for pointing a gun at his Indiana neighbor in a threatening manner during an argument, according to TMZ.

Officials increased LAPD presence at the event, including undercover officers that were positioned in the crowd.

West Hollywood City Councilwoman Lindsey Horvath said officials do not believe there is any threat to Sunday's celebration.

June is known as Pride Month, an annual celebration to honor the 1969 Stonewall riots.

Omar Mateen, 29, has been identified as the shooter of the horrific Orlando gun massacre that also injured 53 other clubgoers.

An FBI spokesman said Sunday's mass shooting is being investigated as an act of terrorism, adding that they are looking into whether it was an act of domestic or international terror, and if the Mateen was a lone wolf.

The FBI believe Mateen, who was shot dead by officers, may have 'leanings to radical Islamic terrorism'.

But his father, Mir Seddique, told NBC News his son became angry when he saw two men kissing in Miami several months ago.

Officials said they are increasing LAPD presence at the event (pictured on Sunday), including undercover officers that will be in the crowd

Members of the FBI Joint Terrorism task force stand by to provide security for the 2016 Gay Pride Parade

Mayor Eric Garcetti said it is believed the man is completely unrelated to the Orlando massacre. The investigation has since been taken over by the FBI

LAPD deputies could be seen on patrol as tens of thousands of people flocked to the parade

'This has nothing to do with religion,' he said. 'We are saying we are apologizing for the whole incident. We weren't aware of any action he is taking. We are in shock like the whole country.'

LA Pride is a three day weekend festival with scheduled performances from the likes of Carly Rae Jespen and Charlie XCX. Tens of thousands gathered in WeHo for the event.

The parade observed a moment of silence for the victims of the Orlando gay club attack at 10.45am on Sunday.

Signs reading 'We Love Orlando' and '50 lost. Why?' could be seen floating through the crowd, according to Variety.

'We will not shrink away. We will not be stuck in our homes,' Garcetti said during a press conference in support of the LGBT community before the parade on Sunday.

'We will not go back in our closets….We are here to march, to celebrate and to mourn.”

(The death toll had been amended to 49, after police said the previous count of 50 included the gunman)

LA Mayor Eric Garcetti (pictured) said the parade was a day to 'march, to celebrate, to mourn'

One attendee arranges a bouquet of flowers at a memorial with 50 candles for the 50 Orlando victims

Signs reading 'We Love Orlando' and '50 lost. Why?' could be seen floating through the crowd