Ecuador was in a state of emergency Sunday after a powerful earthquake flattened buildings and ravaged towns along the nation's northwestern coast Saturday night.
At least 77 people were killed and 588 were wounded, Vice President Jorge Glas said, after the magnitude-7.8 earthquake struck just before 7 p.m. local time (8 p.m. ET).
President Rafael Correa declared a national emergency, and said the tremblor was the strongest quake to hit Ecuador since 1979. "Our infinite love to the families of the dead," Correa said on Twitter, while cutting short a trip to Italy to return home.
States of emergency were declared for the provinces of Esmeraldas, Los Rios, Manabi, Santa Elena, Guayas and Santo Domingo. The quake was strongly felt in country's capital of Quito, around 100 miles away.
Glas said 10,000 military troops and 3,500 police have been dispatched to the affected areas. Meanwhile, the Home Ministry said five helicopters and over 80 buses were ferrying 4,000 police to the quake zone.
Authorities said landslides were making it difficult for emergency workers to reach the towns hardest hit by the earthquake.
"We're trying to do the most we can, but there's almost nothing we can do," said Gabriel Alcivar, mayor of Pedernales, a town of 40,000 near the quake's epicenter, according to the Associated Press.
Alcivar pleaded for authorities to send earth-moving machines and emergency rescue workers as dozens of buildings in the town were flattened, trapping residents among the rubble. He said looting had broken out amid the chaos but authorities were too busy trying to save lives to re-establish order.
"This wasn't just a house that collapsed, it was an entire town," he said.
The country's Geophysics Institute in a bulletin described "considerable damage" in the area of the epicenter and in Guayaquil.
The quake's epicenter was 16 miles south-southeast of the coastal town of Muisne, located on the country's northwestern coast, the U.S. Geological Survey said. The quake was recorded at a depth of about 12 miles.
One person was killed when an overpass collapsed and crushed a car in the country's largest city, Guayaquil, located 200 miles to the south of Muisne. Another occupant of the car survived and was taken to a hospital, authorities said.
Video posted online showed damage to a shopping mall in Portoviejo and people crowded in the street outside as alarms rang. A hotel in Manta partially collapsed and was left barely standing, and buildings were shaken to the ground in Guayaquil.
"I was in my house watching a movie and everything started to shake. I ran out into the street and now I don't know what's going to happen," Lorena Cazares, 36, a telecommunications worker in Quito, told Reuters.
NOAA's Pacific Tsunami Warning Center said tsunami waves up to 3 feet above tide level were possible for some coastal areas of Ecuador, but later said the threat had largely passed. Ecuadorians who were told to evacuate coastal areas for fear of a tsunami were later told to return home.
A smaller 4.5 magnitude quake was recorded along the coast south of Muisne about a half-hour before the magnitude-7.8 quake struck, the USGS said. At least 36 aftershocks followed, one as strong as a magnitude-6, and authorities urged residents to brace for even stronger ones in the coming hours and days.
The earthquake in Ecuador comes just days after the first of a pair of powerful and deadly quakes shook southwestern Japan. At least 41 people were killed in a magnitude-6.5 earthquake Thursday and a magnitude-7.0 earthquake Saturday, national broadcaster NHK reported.
David Rothery, a professor of planetary geosciences at The Open University, northeast of London, says the total energy released by the magnitude-7.8 quake Saturday in Ecuador was "probably about 20 times greater" than the magnitude-7.0 quake in Japan on Saturday.
The Associated Press and Reuters contributed to this report. This story first appeared on NBCNews.com.