A powerful earthquake struck Southern California on Thursday, touching off house fires and damaging buildings in a desert town northeast of Los Angeles, but authorities had no early reports of injuries.

The 6.4 magnitude quake, the largest in two decades in the area, struck about 113 miles (182 km) northeast of Los Angeles near the city of Ridgecrest at around 1:30 pm EDT (1730 GMT), according to the U.S. Geological Survey (USGS).

The Kern County Fire Department said on Twitter it was working "nearly 2 dozens incidents ranging from medical assistance to structure fires in and around the city of Ridgecrest, CA."

Ridgecrest Mayor Peggy Breeden said the city was dealing with fires and broken gas lines, as well as falling objects that hit people, as the city endured many aftershocks.

"We are used to earthquakes but we're not used to this significance," she told MSNBC.

The quake is the largest in Southern California since the 1994 magnitude 6.6 Northridge earthquake, USGS geophysicist Paul Caruso said. That quake, which was centered in a heavily populated area of Los Angeles, caused billions of dollars of damage.

Breeden said she had never felt a quake "like this long rolling" temblor, adding she was driving in her car when it happened and immediately pulled up her emergency brake.

She said the city of Ridgecrest had asked residents to look after others, especially the elderly, which form a large part of the city's population.