A powerful 7.6-magnitude earthquake struck off northern Chile late last night but there were no reports of damage.
A precautionary tsunami alert along the coast and in neighbouring Peru has been called off.
It was the strongest of several aftershocks that followed a huge 8.2-magnitude quake blamed for six deaths in the same region on Tuesday.
Chile's emergency office Onemi said there were no initial reports of casualties or serious damage from the latest quake.
President Michelle Bachelet, who had gone to the area to inspect the damage from the earlier quake, was evacuated from her hotel in the city of Arica.
"I was evacuated like all the citizens and we have come here [to Arica's emergency office] to see if there is any way we can help," she said late last night.
The area is home to many of the biggest mines in Chile, the world's top copper producer.
A spokeswoman for Glencore Xstrata's and Anglo American's Collahausi mine said the "process of normalisation" it was following after Tuesday's quake was continuing without problems.
Other mines could not immediately be reached for comment, but they were generally unaffected by Tuesday's stronger quake.
Chile's arid, mineral-rich north is sparsely populated, with most of the population concentrated in the port towns of Iquique and Arica, near the Peruvian border.
The new quake was located 19km south of Iquique at a relatively shallow depth of 20km, the US Geological Survey said.
The Pacific Tsunami Warning Centre said that while there was no widespread tsunami threat, the latest tremor could generate a local tsunami.
The bigger earthquake on Tuesday triggered a tsunami with 2m waves and officials said it caused six deaths.
More than 2,600 homes were damaged and fishing boats along the northern coast were destroyed. However, most infrastructure held up.
Chile is one of the most earthquake-prone areas of the world. In 1960, southern Chile was hit by a 9.5 quake, the largest in modern history.