SAN DIEGO - Authorities say a swarm of earthquakes that struck southeastern California has knocked 20 mobile homes from their foundations and cut power to 2,500 people.

The U.S. Geological Survey says the largest quake Sunday registered at a magnitude 5.5, and was centered near the town of Brawley. More than 30 other quakes with magnitudes of at least 3.5 shook the same area.

A spokeswoman for the Imperial County Emergency Operations Center says about 20 families were displaced after the quakes shifted the mobile homes from their foundations. Sporadic power outages also prompted authorities to evacuate some patients from one of the county's two hospitals.

No injuries have been reported.

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