Chile is continuing to feel powerful aftershocks a week after the massive earthquake and subsequent tsunami occurred.
They measured up to magnitude 6.6 and caused damaged buildings to topple in Concepcion.
The US Geological Survey says aftershocks will be felt for months and possibly years.
Geophysicist John Bellini said: "The larger the earthquake, the larger the aftershocks, the more of them and the longer they're going to last."
However, he said, they will wind down in number.
There have been more than 200 aftershocks since a magnitude 8.8 earthquake occurred at 3.34am on Saturday, 27 February. It was the worst disaster to befall Chile in 50 years.
The epicentre of the quake was 115km north-east of Concepcion and 325km south-west of the capital Santiago.
About two million people are believed to have been affected. About 1.5 million houses were damaged.
United Nations Secretary General Ban Ki-Moon is now in Chile to assess the damage.
The government of outgoing President Michelle Bachelet, facing criticism for its slow response to the quake, said it was revising the death toll after authorities mistakenly tallied scores of missing people who later turned up alive.
Officials said they had now identified 452 victims. They did not give a number for unidentified bodies or missing people and backed off a previous figure of more than 800 deaths.
Many people who survived the 27 February quake were killed hours later by a massive tsunami, outraging Chileans who say there was no warning the waves were coming.
Navy official sacked
Chile has sacked the head of the Navy's Oceanography Service, saying he failed to provide a clear warning of the tsunami that followed the huge earthquake.
Military officials have said there was an error of diagnosis and unclear information was relayed to President Michelle Bachelet on whether to lift or maintain a tsunami alert along the coast.
In a series of contradictory official messages, an alert was issued and lifted multiple times while three waves struck the coastline.