Quito: At least 233 people have been confirmed dead and 500 people were injured as a 7.8 magnitude earthquake struck Ecuador on Saturday evening, President Rafael Correa said on Sunday.
According to BBC, around 10,000 troops and 3,500 police personnel have been deployed in the affected areas.
Officials said the toll was likely to rise, as one of the most powerful quake in decades was felt as far away as neighbouring Colombia.
President Correa gave the latest toll on his Twitter account, while flying back from Italy, a visit he cut short after the disaster.
Rescue workers work to pull out survivors trapped in a collapsed building after a huge earthquake struck, in the city of Manta. Pic/AFP
He declared a state of emergency and called on his country to be "calm and united".
Vice President Jorge Glas said: "These are very difficult moments.
"We have information that there are injured people who are trapped (under rubble) in different districts and we are getting ready to rescue them," BBC quoted him as saying.
Saturday's quake was reported to be Ecuador's biggest since 1979. More than 130 aftershocks have followed.
The US Geological Survey said the quake struck at a fairly shallow depth of 19.2 km, about 27 km from Muisne in a sparsely populated area.
The quake was also felt in Colombia, where patients in a clinic in Cali city were evacuated from the building.
In Ecuador, helicopters and buses ferrying troops have been hampered by landslides.
People were using their bare hands to try to dig out survivors in some areas.
Food and other essential items were handed out, with aid also coming from Venezuela and Mexico.
Widespread damage has been reported, with a bridge destroyed in Guayaquil about 300 km away, BBC said.
Gabriel Alcivar, the mayor of Pedernales, which is close to the epicentre, said the "entire town" was flattened.
"We are trying to do the most we can but there is almost nothing we can do," he said, adding that incidents of looting have been reported.
Rescue workers evacuate people from a wrecked building. Pic/AFP
In Manta, one of the badly hit areas, a woman survivor said: "The third floor collapsed on top of us. They are all there, my family, my sister, my children. They are all there, there are a lot of people. My god, may help arrive."
Cristian Ibarra Santillan was in capital Quito when the quake struck.
"There had been some small tremors going on for about two or three months and I thought it was one of those but after about 20-30 seconds it started to get really strong," he told BBC.
"And I grabbed my dog and I hid under the table. But then I realised that it wasn't going away so I just ran with him outside."
Reports say a big oil refinery had been temporarily shut as a precaution, BBC said.
Neighbouring Peru also issued a tsunami alert for its northern coastline.
The quake was felt in Colombia, where patients in a clinic in the city of Cali were evacuated from the building as a precaution.
Ecuador is located in a region with frequent volcanic eruptions and earthquakes.