UPDATE 4-Magnitude 6.8 quake shakes Chile, but no serious damage
* Strong earthquake hits near central-northern town of Copiapo
* Buildings sway as far away as capital Santiago
* 50-year-old woman dies of heart attack following quake (Updates with death of woman who suffered heart attack, comments from regional mining authority)
SANTIAGO, Jan 30 (Reuters) - A strong magnitude 6.8 earthquake hit central-northern Chile on Wednesday, shaking buildings as far away as the capital Santiago, and possibly leading a woman to die minutes later of an apparent heart attack, the U.S. Geological Survey and local officials said.
There were no reports of serious damage.
The quake, initially reported as a magnitude 6.7, struck at a depth of 28.4 miles (45.7 km), 63 miles southwest of the mining town Copiapo and 364 miles north of Santiago at 5:15 p.m. (2015 GMT), the U.S. Geological Survey said.
A 50-year-old woman in Copiapo died after presumably suffering a heart attack following the quake, Chile's Onemi emergency office said.
The earthquake hit well south of large mines in the world's top copper producer and Chile's emergency office said there were no preliminary reports of significant damage.
"Mining companies have reported some minor rock falls on auxiliary roads ... the companies' personnel are fine and there are no structural damages to speak of," said Copiapo's regional mining authority Mauricio Pino.
The navy said the quake did not meet the conditions needed to generate a tsunami off the country's Pacific coastline.
Nearly three years ago, a massive 8.8-magnitude earthquake and ensuing tsunami ravaged central-southern Chile, killing hundreds of people and causing billions of dollars worth of damage.
The mayor of Vallenar, a town close to the epicenter, told CNN Chile some walls had collapsed in lower-income areas with poorer quality buildings.
Television showed images of minor damage to homes such as broken windows and bottles of cooking oil thrown from their shelves in a local supermarket. (Reporting by Santiago newsroom and Sandra Maler in Washington; Writing by Alexandra Ulmer and Anthony Esposito; Editing by Jim Loney and Lisa Shumaker)