June 11 (Reuters) - A 5.0 magnitude earthquake shook South Africa's Johannesburg on Sunday morning, the U.S Geological Survey (USGS) said. The USGS said the earthquake occurred at 0038 GMT at a depth of 10 km (6 miles). "Earth tremor in Johannesburg. Went on for about 30 seconds, it felt like," one resident wrote on Twitter. Security risk and crisis management consultancy Crisis24 said there were no reports of damage or casualties as a result of the earthquake.

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Persons: Crisis24, Nelson Banya, Alex Richardson Organizations: U.S Geological Survey, Twitter, Thomson Locations: South Africa's Johannesburg, Johannesburg