Ecuador's strongest earthquake since 1979 killed at least 272 people, caused widespread damage and prompted the government to deploy thousands of soldiers to the quake zone.
The 7.8-magnitude tremor that struck Saturday evening some 170 kilometres north-west of the capital Quito also left more than 2,500 injured, President Rafael Correa said late Sunday, according to media reports.
The government deployed 10,000 soldiers and 4,000 police officers to the affected areas, while workers from abroad were on their way to support rescue efforts.
Correa thanked the world for its "solidarity" during the disaster and urged Ecuadorians on his Twitter feed to exercise care near quake-damaged buildings and power poles.
He arrived back in Ecuador from a trip to Italy and the Vatican and went directly to the cities of Manto and Portoviejo in the disaster zone, CNN reported.
A state of emergency is in place in five coastal provinces, his office said. The president said emergency shelters would be erected and that two mobile hospitals were being put in place.
Dozens of aftershocks, several of them magnitude 5.0 or greater, rattled the country in the hours after the quake hit.
There were widespread reports of power outages and road closures, with the destruction also wreaking havoc in Ecuador's largest city, Guayaquil.
Around 100 prisoners escaped following the earthquake, Justice Minister Ledy Zuniga said on Twitter. About 30 prisoners were recaptured in Portoviejo in the western province of Manabi, one of the most badly affected regions.
El Comercio newspaper reported that Pedernales, a coastal town popular with tourists, remained cut off from outside help.
The quake came as a result of movement at or near the plate boundary between the Nazca and Pacific plates, the US Geological Survey said.
Ecuador - on the so-called Pacific "ring of fire" - has a history of large quakes. Since 1900, seven magnitude-7 or greater earthquakes have had an epicentre within 250 kilometres of the latest quake, the US agency said.