Los Angeles was jolted awake Monday by a shallow earthquake with a magnitude of 4.4 that jangled nerves in the West Coast but caused no major damage or casualties.

Car and burglar alarms went off and a few objects fell off shelves after the tremor, which struck just before dawn with its epicenter some 20 miles (32 kilometers) northwest of Los Angeles, at a depth of only five miles.

It was the most significant shaking caused by an earthquake in southern California since one with a magnitude of 5.5 in 2008.

"I woke up to feel the building swaying from side to side," Wes Lashley told KCAL 9 news, while local resident Mary Lyon added: "It felt like a 5.9 or 6 to me."

The quake was initially estimated as a magnitude 4.7 by the US Geological Survey (USGS), but later downgraded it to 4.4.

But it felt stronger to many Angelenos. One AFP reporter in the Hollywood neighborhood said several objects fell off shelves.

Morning news anchors on the local KTLA television station dove under their desk as the quake visibly shook the studio around them.

No disruption was reported at the city's LAX airport, although Metro trains were delayed as engineers checked tracks for damage, officials said.

USGS seismologist Robert Graves said small aftershocks would likely continue for a few days, while there was a five percent chance that the quake was a forerunner to a larger earthquake.

"This is a reminder that we live in earthquake country here in southern California," he told reporters.

Los Angeles resident Yvonne Villanueva told KTLA: "I was getting ready in the bathroom and all of a sudden I felt it jolt... You always have the big one in the back of your head."

The quake was centered six miles northwest of Beverly Hills and struck at 6:25 am (1325 GMT).

"I woke up to feel the building swaying from side to side," Wes Lashley told KTLA.

The quake came a week after a powerful 6.9-magnitude earthquake struck off the coast of northern California, the biggest in years.

California has long braced for the "Big One."

The western state is on the so-called Ring of Fire, which circles the Pacific and has produced a number of devastating quakes including Japan's March 2011 quake-tsunami, which killed thousands of people.

Geologists say a quake capable of causing widespread destruction is 99 percent certain of hitting California in the next 30 years.

A magnitude 7.8 quake could kill 1,800 people, injure 50,000 more and damage 300,000 buildings.

A 6.7-magnitude earthquake in Los Angeles left at least 60 people dead and did an estimated $10 billion damage in 1994, while a 6.9 quake in San Francisco in 1989 claimed the lives of 67 people.

"Today's earthquake is a reminder that every LA family must be prepared with food, water and other essentials, as well as a plan," said Mayor Eric Garcetti.