TIJUANA, Mexico, Aug 3 (Reuters) - A strong 6.9-magnitude earthquake struck off Baja California in northwestern Mexico on Monday, shaking buildings as far away as San Diego, California, and raising fears of a small tsunami.
The U.S. Geological Survey said the quake struck inside the Sea of Cortez, 76 miles (122 km) from the town of Santa Isabel on the Baja California peninsula and was 6.2 miles (10 km) deep. The figures were revised from its initial estimates.
There were no initial reports of deaths or serious damage. Baja California, home to desert and mountains, is sparsely populated.
The quake was felt strongly in San Diego just across the border from Mexico and City Hall was evacuated, local media said.
"It felt very calm, there was barely a vibration," said hotel receptionist Graciela Alvarado at a motel in the town of Caborca, in the Mexican state of Sonora, across from Baja California.
Local authorities and the USGS warned there was a risk of a small, localized tsunami in the area but no official tsunami warning for the main Pacific coastline.