A magnitude 7.6 earthquake struck in northern Chile Wednesday, U.S. seismologists reported, just a day after another powerful tremor off the South American nation's coast caused a tsunami and left several dead.
A second quake this week struck about 25 miles southwest away from the northern Chilean port city of Iquique, the U.S. Geological Survey reported Wednesday.
No new major damage or casualties were reported.
After the 7.6-magnitude aftershock struck just before midnight Wednesday, Chile's Emergency Office and navy issued a tsunami alert and ordered a precautionary evacuation of low-lying areas for the country's entire 2,500-mile Pacific coastline. The aftershock was originally reported as 7.8-magnitude but was downgraded as often happens as scientists better understand the event.
Among those moved inland was President Michelle Bachelet, who was in the city of Arica assessing damage in the north from Tuesday night's powerful quake.
"I was evacuated like all citizens. One can see that the people are prepared," she tweeted early Thursday.
Chile's evacuation order initially applied to the full coast, but authorities quickly lifted the alert for all but the far-northern shore and even ended it there around 2 a.m. Thursday. The whole coast also was evacuated for several hours after Tuesday's quake, and for the night in the north, although the tsunami proved small.
The aftershock caused buildings to shake and people to run out into the streets in the port of Iquique, which was one of the cities that saw damage from the Tuesday earthquake. There were no immediate reports of serious damage or injuries from the aftershock, which was one of dozens that have followed the magnitude-8.2 quake.
State television said the aftershock caused some landslides near Alto Hospicio, a poor area in the hills above Iquique where about 2,500 homes were damaged by Tuesday' earthquake.
The Ministry of Education suspended classes again in schools in the north for Thursday.
The aftershock was felt across the border in southern Peru, where people in the cities of Tacna and Arequipa fled buildings in fear. Police Lt. Freddy Cuela in Tacna said no damage or injuries were reported. Peru's navy tweeted a tsunami alert for the country's extreme southern coast, which is next to the Chilean region hit by the quakes.
Earlier, authorities reported just six deaths from Tuesday's magnitude-8.2 quake, but didn't rule out the possibility others could have been killed in older structures made of adobe in remote communities that weren't immediately accessible.
Chile is one of the world's most earthquake-prone countries, and tsunamis are a particular danger because of activity in the fault zone just offshore where the Nazca tectonic plate plunges beneath the South American plate.
The strongest earthquake ever recorded on earth also happened in Chile — a magnitude-9.5 tremor in 1960 that killed more than 5,000 people.
Al Jazeera and wire services