A powerful second earthquake hits Southern California

A powerful magnitude 7.1 earthquake shook Southern California on Friday, triggering fires, buckling part of a highway, damaging buildings but causing few reported injuries despite striking with eight times more force than the initial quake in the same area a day earlier.

US meteorologists say that it was the biggest tremor to strike California in two decades.

The quake struck at the shallow depth of 0.9km (0.6 miles) and its epicentre was near the city of Ridgecrest, about 240km north-east of Los Angeles.

A 6.4 magnitude quake hit the same region on Thursday at a depth of nearly 11km.

The latest quake struck at about 8:20 p.m. local time (0320 GMT) near the town of Ridgecrest on the edge of Death Valley National Park, about 125 miles (202 km) northeast of Los Angeles, according to the U.S. Geological Survey (USGS).

It was also measured at 7.1 by the European-Mediterranean Seismological Agency.

The San Bernadino County Fire Department reported that Friday's quake had caused some damage to buildings.

"Homes shifted, foundation cracks, retaining walls down," the department said on Twitter. "One injury (minor) with firefighters treating patient. No unmet needs currently."

A swarm of strong aftershocks have jolted the high desert region of Southern California since a 6.4 quake on Thursday morning. Only a few injuries were reported in Thursday's quake but two houses caught fire from broken gas pipes, officials said.

The USGS said Friday's earthquake was about 11 times more forceful than Thursday's tremor, which geologists described as a foreshock to the larger one.