LOS ANGELES (Bloomberg) — A fast-moving brush fire north of Los Angeles scorched more than two dozen acres as it raced up steep hills and burned heavy brush less than a quarter mile from the famous Hollywood sign that overlooks the city.The fire, which started in the 3600 block of Barham Boulevard in the north of Los Angeles, was first reported at just five acres before quickly spreading up the Hollywood Hills covered in dry brush and shrubbery. Firefighting crews from Los Angeles City Fire Department, Los Angeles County Fire Department and Glendale fire department are tackling the blaze.

More than 200 firefighters are on the scene and the fire has spread across 25 acres, said Los Angeles Fire Department spokesman Ron Myers in a telephone interview.

"There are no reports of injuries or structural damage so far, and that includes the Hollywood sign," he said. The fire is now burning eastward in the direction of Griffith Park and the neighborhood of Los Feliz.

Fire crews also have a bulldozer that's cutting "vegetation away from the fire," said Los Angeles County Department firefighter German Aguilera in a telephone interview.

Five helicopter air tankers are working to drench the blaze and stop it from spreading further, he said. Thick dark plumes of black and gray smoke obscure parts of the hilly ridge where the fire is burning. The smoke can be seen for miles and is drifting south across the city.

Firefighting crews are using the top of Mount Lee, site of the landmark Hollywood sign, as a staging post to tackle the fire.

"We don't yet know the cause of the fire," Myers said.