Authorities have declared a state of emergency on a second Greek island as a series of earthquakes continued to rattle the south-eastern Aegean Sea region.

The emergency measure announced on the island of Amorgos follows a similar decision for nearby Santorini on February 7 after thousands of unusual tremors were registered in an undersea area

Earlier this month the UK Foreign Office issued travel advice for British tourists in the area - with thousands of earthquakes reported in recent weeks