AFP, Santiago :A powerful 8.3-magnitude earthquake struck off Chile on Wednesday, killing at least eight people, forcing the evacuation of one million and sparking warnings that tsunami waves could even reach Japan.Buildings swayed as far away as in Buenos Aires, Argentina, 1,500 kilometers (1,000 miles) away to the east. In Chile, people ran out into the streets in terror.TV footage showed stores with floors strewn with a colorful and mushy mess of broken bottles, jars and other spilled merchandise.It was the sixth most powerful quake in the history of geologically volatile Chile and the strongest anywhere in the world this year, Deputy Interior Minister Mahmoud Aleuy said. Strong aftershocks followed the first quake, and a tsunami alert remained in effect hours later for the Chilean coast. Many people were evacuated to higher ground.More than 135,000 families were left without power in the north-central coast area, the National Emergency Office reported, lowering an early figure. Central Choapa province, which is closest to the epicenter, was declared a catastrophe zone and placed under military rule.The United States Geological Survey put the shallow offshore quake at a magnitude of 8.3 and said it hit 228 kilometers (about 140 miles) north of Santiago, a city of 6.6 million people.The Chilean government put the main earthquake at 8.4 on the Richter scale.”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.”Interior Minister Jorge Burgos said evacuation of coastal towns and cities had been ordered as a precautionary measure. Classes were cancelled in coastal areas.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 collapsed. Around a dozen people were injured.In coastal La Serena, in the north of Chile, “people were running in all directions,” said resident Gloria Navarro.Waves crashed across costal roads in the regions of Coquimbo and Valparaiso. Rough seas were also forecast for Thursday. “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.