A massive earthquake with a magnitude of 8.8 has hit central Chile, killing at least 64 people, ministers say.
The quake struck at 0634 GMT about 115km (70 miles) north-east of the city of Concepcion and 325km south-west of the capital, Santiago.
President Michelle Bachelet declared a "state of catastrophe" in affected areas and appealed for calm.
Although phone communication out of Chile has been difficult, people have been contacting the BBC via email and Twitter. Below are some of the responses we've been sent.
The quake seemed to last more than two minutes in Santiago. Buildings seemed to resist the quake very well. Communications are very difficult and there is no power in most parts of the city. In my building at least there is no water supply service either. We drove through a built-up part of the city this morning and it seems to have survived without major inconveniences.
Jose L Cruz, Santiago
It was tremendous; the buildings were literally dancing in the air; I've driven through the old downtown and there's no relevant damage, but there are some collapsed bridges. I'm worried about the people who lives near Concepción, because their comunications are broken down, so no one knows about the damage of a earthquake of that magnitude.
I think what would happen if an earthquake like this takes place in middle east; thanks god we are prepared for any disaster of that type.
Nicolás, Santiago, Chile
We are in Santiago. Quake lasted about thirty seconds. Buildings shook violently. Seem to all have withstood structural damage but there is broken glass. Interior damage worse. Was terrifying. People still out on streets. Electricity down in many areas and no phones. We crouched in bathtub on fourteenth floor during the quake while things smashed around us. Still getting after tremors.
Charlotte Mountford, Santiago
Yes, I felt it at 3:40am, we were in bed but woke up with the shaking. We all went outside and stood below a door frame and it lasted quite some time and we have felt a number of aftershocks since. We had no electricity or phones although but power has now been restored. I still can't contact all our family in Concepcion because it seems that none of the mobile or fixed phones seem to be working. I am now sitting in bed with clothes and shoes on just in case...
Jessica Rodriguez, Santiago, Chile
I am in the La Reina/Las Condes area of Santiago. It's OK on our few streets - lasted about two minutes. It's 0430 now and roads mad with traffic and everyone out in streets fearing aftershocks.
I am a university professor that lives in Santiago. This is a massive earthquake since 1986 and the cities resisted well and communications by internet 3G are fine but not mobile phones yet. Santiago seems quiet with a brilliant moon.
Cristian Bonacic, Santiago
Things were certainly moving a bit, but no structural damage visible. Some fires could be seen in the distance. No electricity at the moment or phone lines, but apart from that, so far not so bad.
Mark Winstanley, Vina Del Mar, West of Santiago
We have also been shaken at this side of the Andes in Argentina. We could feel it for about one minute and again after 10 minutes. There was no panic but I guess this has been the strongest we have had in many years.
Diego, Mendoza, Argentina
I live in Mendoza and the earthquake was felt pretty strongly here. I am listening to the radio and it was felt in other provinces like San Luis , Neuquen and Cordaba too.
Graciela Martin, Mendoza, Argentina
Right here in Pergamino (200km north of Buenos Aires and about 1800km from Concepcion, Chile) we were at 0345 in the living room, when suddenly we started to see the very big lamp hanging from the ceiling started to move very fast making circles.
Enzo, Pergamino, Buenos Aires, Argentina