More than 400 arrests made in Fourth of July celebrations in Newport Beach

Illegal fireworks and fights in Newport Beach tonight.We're learning much more about what sparked the 4th of July chaos.Officers say they were forced to move in and make more than 400 arrests.NBC4's Tracy Leong has been digging into what happened.She joins us now live with the latest.Tracy.

Yeah, Kathy, and about half of those 400 arrests that were made last night were for people who were refusing to leave this area after officers declared an unlawful assembly.Take a listen.video captured the chaos that unfolded on the Balboa Peninsula in Newport Beach during the 4th of July.You can see hundreds of people gathering inside the pavilion's parking lot, setting off fireworks, throwing watermelons and water bottles at the crowd and the police officers.One officer was struck with a mortar.He was treated and is expected to be okay.

Multiple fights also broke out between the crowds of people and the police, and many people were also standing in the roadways, blocking traffic, forcing police to close down several streets.City officials say social media posts drew large crowds of juveniles and young adults to Newport Beach late last night and they engaged in dangerous and unlawful behavior.Police were seen in riot gear ordering people to leave after declaring an unlawful assembly.About 350 Newport Beach police officers as well as 17 nearby law enforcement agencies responded last night.The Newport Beach Fire Department responded to about 100 emergency incidents yesterday including 10 and they transported 44 people to local hospitals, including six trauma patients.I spoke to a family who is staying right across from the pavilions.

Here's how they described what they saw.

It was insane.Mass quantities of kids of all ages.We don't know if they were teenage.We couldn't tell if they were high schoolers.There was a lot of underage kids, a lot.And they were just running up and down.

I mean, we kept seeing stuff getting thrown in the air.And we realized later that they were the water bottles that they were stealing from the front of the store.It was just nuts.It was madness.

When the fireworks were really going off, You know, we were keeping a keen eye as well on any kids with backpacks who were just trying to ignite them wherever they wanted to.And there was a few times where we told the kid, hey, not here, you know, do it elsewhere.Because like I said, they were low level explosives and they should be up in the air.But it was just it was pretty chaotic, insane.

Newport Beach police plan to have an increased presence throughout the holiday weekend.The city also says that compared to last year, they had 60 arrests compared to 402 that they had this year for the same time period.Reporting live in Newport Beach, Tracey Lingong, NBC 4 News.

Tracey, thank you.