Los Angeles police said they responded in force to a section of Hollywood Boulevard after a large group of skateboarders took over the heavily trafficked roadway Saturday night.

Aerial video showed many dozens of people in the street, and a phalanx of patrol cars on Hollywood Boulevard. Officers were seen running toward the group, which began to scatter.

A group of 400 skateboarders were in the street, and the Los Angeles Police Department had responded with a modified tactical alert, according to Sgt. Rudy Lopez.

Shopkeepers had been advised to close their businesses and lock their doors, according to an employee of Juicy Burger.

The incident began about 9 p.m. near Hollywood Boulevard and Vine Street (map).

A man identifying himself as an ESPN skateboard writer on Twitter was at the scene and tweeted about the ongoing incident, saying the crowd was in Hollywood for the premiere of "Bake and Destroy" at the Vine Theater.

"People were cool but then around 830 people were hitting each other with beer cans, throwing cigs at pedestrians & starting fights," HaitianReggie tweeted.

More than 20 patrol cars were seen at the intersection of Hollywood Boulevard and Ivar Avenue.

No other information was available as of midnight.