HOLLYWOOD — A self-described hardcore hip-hop group from Orange County caused havoc on the southbound 101 freeway near Sunset Boulevard Tuesday morning when they began performing atop its truck.

California Highway Patrol officer Terry Liu said the agency began getting calls about the incident at 10:20 a.m. Three people were arrested on suspicion of unlawful assembly, Liu said.

According to Liu, witnesses reported the group was performing on top of a truck while blocking three lanes of the freeway.

Liu said it appears that the driver of the truck got into another vehicle and took off with the keys. Officers had to request a tow truck to remove the band’s truck.

Traffic backup almost reached the I-405, Liu said.

“This type of behavior is not acceptable,” Liu said. “Our officers were tied up on scene trying to handle this while they could have been handling other business or other emergency incidents occurring nearby but instead they were stuck having to deal with this.”

The group, called Imperial Stars, is based in Westminster, according to the band’s Facebook page. Their latest song is called “Traffic Jam 101.”

According to their website, the band is set to “transform the Orange County music scene by epic proportions.”

The CHP is still investigating the incident.

Contact the writer: amolina@ocregister.com or 714-704-3795