LOS ANGELES (Bloomberg) — A fast-moving brush fire north of Los Angeles scorched more than 150 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 on the city's north side, was reported at 12.55 p.m. at before quickly spreading up the Hollywood Hills covered in dry brush and shrubbery. Firefighting crews from the Los Angeles City Fire Department, Los Angeles County Fire Department and Glendale Fire Department are tackling the blaze.

"We have the fire pretty much contained, and there were no firefighter injuries, no civilian injuries and no structures burned," Los Angeles Fire Department Captain Antoine McKnight said in an interview on NBC4.TV. "Things are dry, so we need homeowners to keep their homes clear of brush."

Arson investigators will assess the region and the area where the fire first began, he said. McKnight didn't immediately return a message Bloomberg News left on his cellular phone.

More than 200 firefighters were on the scene at the height of the blaze, Los Angeles Fire Department spokesman Ron Myers said 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 neighbourhood of Los Feliz.

Myers said authorities don't know the cause of the fire.

Fire crews are using a bulldozer to cut vegetation away from the fire, Los Angeles County Department firefighter German Aguilera said in a telephone interview.

Five helicopter air tankers are working to drench the blaze and stop it from spreading, 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 Mount Lee, site of the landmark Hollywood sign, as a staging post to tackle the fire.

The sign, built on the hill in 1923, was first a giant advertisement for a real estate development before it was embraced as a symbol of the city's entertainment business, according to the sign's official website. The sign became an official historical monument in 1973.

Ground crews from the fire departments are moving into positions to tackle hot spots developing on the burning hill. The ground and vegetation in southern California is dry after months of little rainfall

In downtown Los Angeles, 2.47 inches of rain have fallen since last July 1, 82 percent less than the 13.8 inch average, making this the driest winter date since record keeping began in 1877, Stuart Seto, weather specialist at the National Weather Service in Oxnard, California, said in an interview.

"There's about 10 percent humidity up around the fire," he said. "That increases the fire danger because things are really dry and catch fire more easily. Firefighters have to use more water."

The fire is about a mile from Griffith Park, the largest municipal park with an urban wilderness area in the US. The 4,210-acre park is home to Los Angeles Zoo and the Griffith Observatory, which reopened in November after being closed for four years for renovations.

The Observatory didn't move to evacuate visitors. Michael Dee, general curator of the Los Angeles Zoo, said the fire is unlikely to harm the zoo, which is surrounded by a sprinkler system. The biggest risk is that helicopter tankers would frighten the animals, he said.

"I won't be leaving until the fire is out," Dee said.