A magnitude-7.8 earthquake has struck off Ecuador's Pacific coast.  At least 77 people are dead, and hundreds more, injured.

The US Geological Survey says the tremor was centered 27 kilometers southeast of the coastal town, Muis-ne.  It came after a magnitude-7.3 tremor jolted the southern Japanese island of Kyu-shu.

The quake in Ecuador struck at a depth of 20 kilometers Saturday night.  It was followed by 55 aftershocks, with the biggest reaching a magnitude of 5.4. Some 483 kilometers from Muisne, a heavily transited bridge in Guayaquil also collapsed.

A state of emergency has been declared in six provinces and the National Guard has been mobilized. The Andean nation's government recommended residents leave coastal areas after a tsunami warning was issued. The local government has described it as the worst quake in the country since 1979, when nearly 600 people were killed.