A pack of as many as 15 bikers brutally beat a man after accosting him out of his car in the middle of a busy San Francisco highway.
The entire ordeal was caught on video by horrified onlookers in surrounding cars.
The unidentified victim is in fair condition after the ordeal Wednesday when his car was herded into a complete stop by almost a dozen "dirt bikes and ATV's" during rush hour on San Francisco's 101 highway, according to the California Highway Patrol.
A cellphone video shows the victim's car colliding with one of the bikers on the highway around 6:15 p.m., leading to the group surrounding the car and striking it with their fists and bikes.
This led the man to jump out and start running — but he was immediately grabbed by one of the bikers, the video shows. The biker then begins violently punching and kicking him until he falls to the ground, the video shows.
Several members of the group join in the attack, with others smashing the victim's car.
The victim, who is a ride share driver in his 30s, suffered a broken leg, said Vu Williams, an officer with the California Highway Patrol.
The 10 to 15 bikers bolted before authorities could make any arrests, said Williams.
"They are very quick and very mobile," he said. "They remove plates on their vehicles and cover their faces so it's not always easy to identify them."
And they've also grown bolder, as incidences involving reckless bikers have increased within the past few years in the area, he said. The usual M.O is the side show of wheelies and bike tricks that stop or obstruct traffic, but it's rare for them to get into a physical altercation with a motorist, he said.
The attack was reminiscent of similar bloody street brawl in New York when group of riders swarmed around and SUV of Alexian Lien after he clipped the back tire of one of the bikers in 2013.
The group violently beat Lien in front of his wife and toddler daughter who were also in the car.
One of the riders arrested was a New York City police officer who was undercover at the time.
While California law enforcement is still hunting for the assailants in the San Francisco attack, onlooker's videos have "sparked several calls from the public on leads to their identities," Williams said.