Northern Chile was rocked Monday by a strong aftershock in the same coastal area hit last week by an 8.2-magnitude quake, authorities said. No damage or casualties were reported.

The National Seismological Center of the University of Chile said the latest tremor, which occurred at 10:43 am (1343 GMT), had a 6.1 magnitude. The US Geological Survey put it at 5.8.

There was no risk of a tsunami, according to the Chilean Navy's Hydrographic and Oceanographic survey.

"No damage to people or alteration of basic services or infrastructure resulted from this quake," the National Emergency Office said in a statement.

The 8.2-magnitude quake last Tuesday killed six people and forced a million to leave their homes in the region around Iquique, 1,800 kilometers (1,100 miles) north of the capital Santiago.