A 7.9 magnitude earthquake shook the San Jose area of Costa Rica early Wednesday, sending vibrations through buildings and cutting out power in areas of the country's capital city, a Reuters correspondent and the U.S. Geological Survey reported.

Reports indicate that the quake hit close to Samara, a coastal area on the Pacific some 151 kms (94 miles) from the capital city. A Caribbean-wide tsunami watch is in effect, the Pacific Tsunami Warning Center said.