Several hundred people were killed and thousands were injured when a powerful 7.8-magnitude earthquake struck Ecuador, destroying buildings and a bridge and sending terrified residents scrambling from their homes, authorities said Sunday.
Vice President Jorge Glas said the death toll will likely rise in what he called the "worst seismic movement we have faced in decades."
The quake, which struck at 2358 GMT Saturday about 170 km northwest of Quito, lasted about a minute and was felt across Ecuador, northern Peru and southern Colombia.
"Oh, my God, it was the biggest and strongest earthquake I have felt in my whole life. It lasted a long time, and I was feeling dizzy," said Maria Torres, 60, in the capital Quito, which was rocked by the late Saturday quake.
"I couldn't walk... I wanted to run out into the street, but I couldn't."
Glas said early Sunday that the number of confirmed deaths has reached 77, and that more than 588 people were injured.
"We know that there are citizens trapped under rubble that need to be rescued," he said in a special TV and radio broadcast.
Officials declared a state of emergency in the six worst-hit provinces.
Police, the military and the emergency services "are in a state of maximum alert to protect the lives of citizens," Glas said.
President Rafael Correa, on a visit to the Vatican, wrote on Twitter that he was immediately returning to Ecuador.
In the Pacific port city of Guayaquil, home to more than two million people, a bridge collapsed, crushing a car beneath it, and residents were picking through the wreckage of houses reduced to heaps of rubble and timber, an AFP photographer reported.
Ecuador's Geophysical Office reported "considerable" structural damage "in the area near the epicenter as well as points as far away as Guayaquil."
Earthquake zone The US Geological Survey (USGS) said the 7.8-magnitude shallow quake struck off the northwest shore of Ecuador, just 27 kilometers from the town of Muisne. The vice president gave a slightly lower measurement of magnitude 7.6.
Ecuador lies near a shifting boundary between tectonic plates and has suffered seven earthquakes of magnitude 7.0 or higher in the region of Tuesday's quake since 1900, the USGS said. One in March 1987 killed about 1,000 people, it said.
At least 55 smaller aftershocks rattled the country after the main quake, Glas said.
The Hawaii-based Pacific Tsunami Warning Center initially issued a warning for the nearby Pacific coastline but later said that the threat had largely passed.
David Rothery, a professor of geosciences at The Open University, said the quake's 7.8 magnitude meant that "shaking at its underground source was about 6 times stronger than in the magnitude 7.0 earthquake in southern Japan just over a day before."
"The total energy involved was probably about 20 times greater," he said, adding that there was no causal relationship between the two quakes.
The quake that hit Japan early Saturday left at least 41 dead.
Rothery said the Ecuador quake was caused by the floor of the Pacific Ocean being subducted under South America.
The rupture occurred deeper underground than the recent Japan quakes, which should have lessened the shaking at the surface, he said.
"The greater damage to buildings and the probable greater loss of life in Ecuador may reflect poorer adherence to seismic building codes in the construction of buildings and bridges," he said.