People stay on higher grounds in a tsunami safety zone after a magnitude 6.7 earthquake shook the region, in Iquique city, north of Santiago March 16, 2014. The strong quake struck off northern Chile on Sunday evening, triggering a preventive evacuation of part of the coastal area but not causing any injuries or damage to the country's crucial copper mines. The Pacific Tsunami Warning Center said there was no tsunami expected. [Photo/Agencies]

SANTIAGO - A strong quake struck off northern Chile on Sunday evening, triggering a brief evacuation of part of the coastal area but not causing any injuries or significant damage.

The magnitude 6.7 quake, originally measured as a 7.0, was centered 37 miles (60 km) west-northwest of Iquique and hit at a depth of 12.4 miles (20 km), the US Geological Survey said.

The ONEMI emergency office said there was no major damage stemming from the shake, which struck at 6:16 pm local time (2116 GMT), save for two small roadside rock falls in the Arica and Parinacota region.

Chile's massive copper mines, clustered in the mineral-rich North, appeared to be fine. Collahuasi, a partnership between Glencore Xstrata and Anglo American, located in the area, said operations were normal.

The Pacific Tsunami Warning Center said following the quake that there was no tsunami expected.

But Chile's navy said there was a possibility of what it called "a minor tsunami", so authorities ordered a preventive evacuation of part of the coastline after the quake.

Sea level rises did not top a negligible 32 centimeters in the area, the ONEMI said.

Local media showed footage of people in Iquique calmly evacuating on foot to nearby hills. Some had been enjoying the sunny Sunday on the beach during the tail end of the Southern Hemisphere's summer.

The evacuation order, which affected over 100,000 people, was called off roughly three hours after the quake happened.