SANTIAGO, Chile -- A powerful magnitude-8.3 earthquake hit off Chile's northern coast Wednesday night, causing buildings to sway in Santiago and bringing flooding from small tsunami waves in some shore towns.
Officials reported three deaths. There were no reports of serious damage hours after the quake, but officials were still checking the region late into the night.
Authorities had issued a tsunami alert for Chile's entire Pacific coast, and the tremor was so strong that people on the other side of the continent, in Buenos Aires, Argentina, reported feeling it.
Numerous strong aftershocks, including one measuring 7.0 magnitude and three above 6, rattled the region after the first major tremor since a powerful quake and tsunami killed hundreds in 2010 and leveled part of the city of Concepcion in south-central Chile.
"Once again we must confront a powerful blow from nature," President Michelle Bachelet said, addressing the nation late Wednesday.
Bachelet said three people had been killed in the quake but gave no details. She urged people who had been evacuated from coastal areas to stay on high ground until authorities could fully evaluate the situation early Thursday.
Late Wednesday, authorities lifted the tsunami warning for Chile's far southern regions. The warnings remained in effect everywhere else, and authorities said school classes would be canceled in most of the country Thursday.
Jorge Medina, a Santiago resident, said he was in an aerobics class when the quake hit.
"People started screaming that everything was shaking," he said.
Officials ordered people to evacuate low-lying areas along the 2,400 miles of Chile's Pacific shore, from Puerto Aysen in the south to Arica in the north. Fishing boats headed out to sea and cars streamed inland carrying people to higher ground. Santiago's main airport was evacuated as a precaution and authorities announced classes would be suspended in the port city of Valparaiso on Thursday.
Chile state TV showed water flowing in streets of Concon, a coastal town known for its beautiful beaches that is close to Valparaiso. Higher water was also seen in other cities but no destructive high waves had been reported.