At least 235 people have been confirmed dead and more than 1,500 people injured after Ecuador was hit by its most powerful earthquake in decades.
Some 10,000 troops and 3,500 police are being deployed in the affected areas, as rescue operations continue.
The magnitude-7.8 quake struck on Saturday evening.
Coastal areas in the north-west were closest to the epicentre and officials say the death toll is likely to rise as information begins to come in.
Ecuador’s President Rafael Correa has cut short a visit to Italy to deal with the crisis.
He has declared a state of emergency and said the priority is finding survivors.
“Everything can be rebuilt, but lives cannot be recovered, and that’s what hurts the most,” he said.
Ecuador’s Vice-President Jorge Glas, visiting one of the worst-hit cities, Manta, met a resident who pleaded for people trapped under rubble.
“We cannot go in with heavy machinery because it can be tragic for the wounded,” Mr Glas told him.
Helicopters and buses are ferrying troops north but have been hampered by landslides.
In some areas people are using their bare hands to try to dig out survivors.
Food and other essentials has been handed out and international aid is also beginning to arrive, with the first coming from Venezuela and Mexico.
Colombia announced it was sending rescue teams with search dogs, and its navy would carry water to the affected area.
Gabriel Alcivar, mayor of Pedernales, close to the epicentre, said the “entire town” had been flattened.
“We’re trying to do the most we can but there’s almost nothing we can do,” he added, warning that looting had broken out.
Widespread damage is reported, with a bridge destroyed as far south as Guayaquil about 300km (190 miles) away.