A powerful 7.8-magnitude earthquake has killed at least 41 people in Ecuador, Vice-President Jorge Glas says.
A state of emergency was declared in six provinces and the National Guard has been mobilised.
The quake, near the coastal town of Muisne, destroyed a bridge in the country's largest city of Guayaquil about 300km (190 miles) away.
The tremor also shook buildings in the capital Quito, forcing residents to flee their homes in panic.
Mr Glas told reporters that emergency services, police and the army were "in a state of maximum alert to protect the lives of citizens."
Quito resident Zoila Villena told the Associated Press news agency: "I'm in a state of panic,"
"My building moved a lot and things fell to the floor. Lots of neighbours were screaming and kids crying," she said.
Parts of the capital were left without electricity for some time. An airport tower in the city of Manta is also said to have been destroyed.
Reports say a big oil refinery has been temporarily shut as a precautionary measure.
Image copyright AFPIn pictures: Ecuador earthquake
The US Geological Survey said the earthquake struck at a depth of 19.2km (11.9 miles), about 27km from Muisne - a coastal town in a sparsely populated area.
Meanwhile, the Pacific Tsunami Warning Centre said "tsunami waves reaching 0.3 to one meter above the tide level are possible for some coasts of Ecuador".
Neighbouring Peru issued a tsunami alert for its northern shore.
The quake was also felt in Colombia, where patients in a clinic in the city of Cali were evacuated from the building as a precautionary measure.
Ecuador is prone to earthquakes. It is located along the so-called Ring of Fire, a horseshoe-shaped, seismically turbulent area of the Pacific Ocean.