A powerful 7.7-magnitude quake has hit north Chile, cracking roads, bringing down buildings and knocking out power.
The quake hit at 1243 local time (1543 GMT), centring on Quillahua village, about 100km north-west of Calama town.
At least two people were killed and more than 100 injured in the city of Tocopilla, the authorities said.
The quake - lasting about 50 seconds - sent panicked residents out into the streets. It could even be felt in the capital Santiago, 1,260km to the south.
Chile's National Emergency Office director, Carmen Fernandez, described it as a "major quake".
"One of the most affected zones could be Tocopilla," Deputy Interior Minister Felipe Harboe said on television.
At least 1,200 houses had been destroyed in the city, leaving 4,000 residents without homes, according to Tocopilla mayor, Luis Moyano.
"Today, the people of Tocopilla are going to have to sleep in the streets," he said.
Twenty people were also hurt in Maria Elena, a small town some 60km south-east of Tocopilla, reported the Chilean news site La Tercera.
At least fifty people were trapped when the Galleguillos road tunnel collapsed, Navy Captain Ignacio Rojas told reporters.
In the town of Antofagasta TV pictures showed cars crushed by the concrete awning of a hotel.
reporter for local Radio Cooperativa said she saw cracks in the tarmac at the airport there.
"It was horribly strong. It was very long and there was a lot of underground noise," Andrea Riveros, a hotel worker in Calama, told news agency AP.
Another worker at a hotel close to Calama told AP the hotel felt "like a floating island" during the quake, which took down power lines, cracked windows and knocked masonry off nearby houses.
"I was very frightened. It was very strong. I've never felt one that strong," Paola Barria said.
Chilean President Michelle Bachelet will visit the region on Thursday and the government is sending a plane loaded with humanitarian supplies to the affected areas.
A 5.7-magnitude aftershock struck the region two hours later, Reuters news agency reported.
As well as in the distant capital Santiago, the quake was felt in neighbouring Argentina, Peru and Bolivia. In the Bolivian administrative capital La Paz buildings were temporarily evacuated but no damage was reported.
The quake happened relatively deep underground, diminishing its destructiveness, says the BBC's Daniel Schweimler in the Argentine capital.
The Pacific Tsunami Warning Center in Hawaii cancelled a regional tsunami alert issued shortly after the earthquake, as no damaging waves had been recorded.
But it cautioned that coastal areas in Hawaii could experience "small non-destructive sea level changes and strong or unusual currents lasting up to several hours".
Two tectonic plates - the Nazca and the South American - clash in this region.
In August more than 500 people died when an 8.0 magnitude quake struck neighbouring Peru just south of the capital, Lima. ( BBC )