LOS ANGELES, July 6 (Xinhua) -- U.S. soldiers have been called into state service to provide assistance after a-7.1 magnitude earthquake hit southern California on Friday, while authorities warned residents to be prepared for possible further aftershocks.
The California National Guard was sending 200 troops, logistical support and aircraft on Friday evening, said David Baldwin, major general of California Military Department, on Saturday.
Baldwin added that the Pentagon had been notified and the entire California Military Department was put on alert.
Friday's temblor, the largest to strike southern California in some two decades, was centered near Ridgecrest, a city in Kern County located 272 km north of Los Angeles downtown.
The powerful quake came only one day after a 6.4 magnitude earthquake struck the region on Thursday morning, and was followed by a series of large and small aftershocks.
Also on Saturday, Governor of California Gavin Newsom said in a release that he had requested a presidential emergency declaration for federal assistance to to the affected residents.
The governor said he had activated the State Operations Center in Mather, California, to its "highest level." The center is working closely with state, federal and local emergency managers and first responders.
Earlier in the morning, Newsom declared a state of emergency in San Bernardino County, following a previous declaration of a state of emergency in Kern County on Thursday.
The two earthquakes have caused widespread structural damage to roads, waterlines and gas lines, which resulted in some structural fires in the regions. No fatalities or major injuries have been reported so far.
The earthquakes and the aftershocks have also caused significant damage to many local businesses and damage assessments are ongoing, said California Governor's Office of Emergency Services on Saturday afternoon.
David Witt, chief of Kern County Fire Department, suggested local residents prepare supplies in case another earthquake hits the area.
According to the forecast of the United States Geological Survey (USGS), over the next week, there is a 9-percent chance that one or more aftershocks could be larger than magnitude 7.1. There will be likely smaller earthquakes over the next week.
Lucy Jones, a seismologist from California Institute of Technology, told a press conference held after Friday's quake about possible aftershocks.
She explained that usually, the aftershock would not be stronger, but about 5 percent of the major quakes might be followed by something even bigger.
"Smaller quakes -- M5s are likely and a M6 is quite possible," she tweeted after the quake.
The multiple earthquakes also left the sprawling U.S. Naval Air Weapons Station China Lake just northwest of Ridgecrest "not mission capable" until further notice, with non-essential active duty, drilling reservists, civilian employees, and dependents authorized to evacuate from the military base.
The Chinese Consulate General in Los Angeles issued a release on Friday night, expressing condolences to those affected by the earthquake.
The Consulate General has not received reports of Chinese citizens seeking help after the disaster, said the release.
The last time southern California saw a major quake was in 1999, when a magnitude-7.1 quake jolted the state in the Hector Mine area of the Mojave Desert.