* Mining companies operating normally
* Isolated losses of power, cellphone signal in Ica
* No tsunami warnings issued for Pacific coast (Updates with 16 people injured)
LIMA, Oct 28 (Reuters) - A magnitude 6.9 earthquake struck off the coast of southern Peru on Friday, shaking buildings in Lima and injuring 16 people near the city of Ica.
Officials said there were no deaths or major damages, though at least two adobe brick homes were knocked down.
The U.S. Geological Survey said the quake, initially reported to have a magnitude of 7, was centered under the sea 31 miles (50 km) southwest of Ica, near where a devastating magnitude 8 quake killed more than 500 people in 2007.
Officials at two local hospitals said they had treated 16 patients on Friday for bruises and fractures caused by falling debris.
RPP radio reported that people in cities along the southern coast ran out of their homes and into the streets during the shaking.
Damages appeared to be limited to a loss of cellphone signals, isolated electricity outages in Ica, and a secondary road that was blocked by debris.
Buildings shook in the capital of Lima, about 185 miles (300 km) north of Ica, but business quickly returned to normal and no tsunami warnings were issued for the Pacific coast.
Shougang Hierro Peru, an iron ore producer that runs the mine closest to the epicenter, said it suffered no damages from the quake.
Southern Copper <SCCO.N>, a major global mining company, said it was operating normally. Most other major mines in Peru, a leading global metals exporter, are located farther away from the quake zone. (Reporting by Lima newsroom; editing by Anthony Boadle)
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