A magnitude-7.1 earthquake struck central Chile, the strongest and longest that many people said they had felt since a huge quake devastated the area two years ago.
Some people were injured by falling ceiling material, but there were no reports of major damage or deaths due to quake-related accidents.
The quake struck about 16 miles north-north west of Talca, a city of more than 200,000 people where residents said the shaking lasted about a minute.
Buildings swayed in Chile's capital 136 miles to the north, and people living along a 480-mile stretch of Chile's central coast were briefly warned to head for higher ground.
Residents were particularly alarmed in Constitucion, where much of the coastal town centre at the mouth of a river was obliterated by the tsunami caused by the 8.8-magnitude quake in 2010.
Panic also struck in Santiago and other cities, with people running out of skyscrapers, and many neighbourhoods were left partly or totally without electrical power. Phone service collapsed due to heavy traffic.
"There are some injuries but nothing serious," said Interior Minister Rodrigo Hinzpeter, who was serving as acting president while Sebastian Pinera is on tour in Asia.
Mr Hinzpeter said authorities were conducting a thorough survey of the affected regions to look for damage.
The Chilean navy's hydrographic and oceanographic service and the national emergency office called off a tsunami warning for most of the central coast after an analysis showed the quake was not the type to provoke killer waves.
The alert was restored for the area closest to the epicentre after police noticed the ocean had retreated about 130 feet from the shore in the towns of Iloca and Duao.
A sharp outsurge of surf sometimes is followed by a tsunami.
Many coastal residents were staying away from the shore in any case, remembering how the government said there would be no tsunami just before huge waves struck after the 2010 quake, killing 156 of the 524 victims of that disaster.
With aftershocks rattled the region, many people living inland did not want to go back inside their homes, either.
In Parral, about 230 miles south of the capital, Mayor Israel Urrutia said a 74-year-old woman died of a heart attack during the quake, and he blamed it on the shaking.
State television reported that parts of the ceiling fell from a church in Maipu, west of Santiago, slightly injuring some parishioners.
Similar problems were reported with the roof of a shopping mall in La Florida, south of the capital.
State copper giant Codelco said its mines were functioning normally.
The US Geological Survey said the quake occurred 19 miles deep.
It was the second significant quake in as many days for central Chile, where people were shaken awake yesterday morning by a 5.1-magnitude tremor that caused no major damage or injuries even though its epicentre was in metropolitan Santiago.