The quake struck at 11:31 a.m. local time 30 miles from the regional capital of Popayan and was felt in Bogota as well as 10 of Colombia's 32 states. The U.S. Geological Survey said its epicenter was 94 miles beneath the earth's surface.
The quake was the most powerful to hit Colombia since a 7.2-magnitude temblor shook the same region in 2004, said Patricia Pedraza of Colombia's geological service.
Security chief Edith Cabeza of Cauca state, of which Popayan is the capital, said the "white city" of 270,000 inhabitants suffered no damage.
Popayan's historical center was largely reconstructed after a March 1983 quake that killed at least 250 people.
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