A woman carries belongings out of a store in Concon, some 110 kilometres northwest of Santiago, after a massive earthquake struck off the coast of Chile.

AFP/Santiago

A powerful 8.3-magnitude earthquake struck off Chile on Wednesday, killing at least eight people, forcing the evacuation of 1mn and sparking warnings that tsunami waves could reach as far as Japan.

Buildings swayed as far away as in Buenos Aires, Argentina. In Chile, people ran out into the streets in terror.

TV footage buildings showed stores with floors strewn with a mushy mess of broken bottles and other spilled merchandise.

It was the sixth biggest most powerful quake in the history of quake-prone Chile and the strongest anywhere in the world this year, Deputy Interior Minister Mahmoud Aleuy said.

The death toll of eight was given by Interior Minister Jorge Burgos.

Aleuy said 245,000 families were left without power.

Central Choapa province closest to the epicenter was declared a catastrophe zone and placed under military rule.

The US Geological Survey (USGS) put the shallow offshore quake at a magnitude of 8.3 and said it hit 228 kilometres north of Santiago, a city of 6.6mn people.

"The motion began lightly, then stronger and stronger," said Santiago resident Jeannette Matte.

"We were on the 12th floor and we were very afraid because it was not stopping. First it was from side to side, then it was like little jumps."

Tsunami warning

Burgos said evacuation of coastal towns and cities had been ordered as a precautionary measure. Classes were cancelled in coastal areas.

"We know there could be more aftershocks and so we must continue to evaluate the situation minute-by-minute," Bachelet said.

A tsunami warning was initially in place for the whole of Chile and Peru's Pacific coastline.

Among the dead were a woman in Illapel, close to the epicenter, and an 86-year-old man in Santiago, where there were scenes of pandemonium as thousands fled swaying buildings.

Hardest-hit Illapel, a coastal city of 30,000, saw its electricity fail and several homes were damaged.

In coastal La Serena, in the north of Chile, "people were running in all directions," said resident Gloria Navarro.

A similar fear seized residents in Argentina.

"We went into a panic and the floor kept moving. We went out into the hallway and down the stairs," Celina Atrave, 65, who lives in a 25-story high-rise near downtown Buenos Aires, told AFP.

The quake, which struck at 7.54 pm (2254 GMT), hit at a depth of eight kilometres, USGS said. Seismologists also reported multiple aftershocks, some of them above 6.0.

The Chilean government put the main earthquake at 8.4 on the Richter scale.

As far as Japan

The Hawaii-based Pacific Tsunami Warning Center said that "hazardous" tsunami waves were possible for some parts of Chile's shoreline, including some three metres above the tide level.

Tsunami waves were also possible in French Polynesia, Hawaii and California, officials said, as well as smaller waves as far afield as Japan and New Zealand.

The first tsunami waves struck Chile's coast, including the tourist city of Valparaiso, local television pictures showed, but there were no immediate details of damage or injuries.

The precautionary alert for Peru was later called off, civil defence officials said, but scared residents in the city of Ilo, close to the border with Chile, remained out on the streets and on higher ground nonetheless.

In April last year, a deadly 8.2-magnitude earthquake in northern Chile killed six people and forced 1mn to leave their homes in the region around Iquique.