Two powerful earthquakes have struck off the coast of Ecuador, just days after a major quake killed 525 people.

A 33-year-old nun from Co Derry, Sister Clare Theresa Crockett, was among those who died.

The latest tremor had a magnitude of 6.1 and was centred about 70 kilometres from the city of Esmeraldas.

The US Geological Survey (USGS) says a smaller quake measuring 4.5 also hit very close to that location.

More than 200 people are still missing following a massive tremor on Saturday, which has left thousands of people homeless.

Thousands of food packages and sleeping kits have been delivered from neighbouring countries.

A national emergency has been declared.