Magnitude 7.3 undersea quake could cause hazardous tsunami waves for coasts within 1,000 km of the epicentre, says US-based Pacific Tsunami Warning Center.

Axar.az reports that Indonesia has issued a tsunami warning after an earthquake of magnitude 7.3 struck its region of East Nusa Tenggara.

The US Geological Survey said Tuesday's quake struck around 100 kilometres north of the town of Maumere at a depth of 18.5 kilometres in the Flores Sea at 0320 GMT.

The Pacific Tsunami Warning Center said, "hazardous waves are possible for coasts located within 1,000 km of the quake epicentre".

The USGS said the chance of casualties was low while noting that "recent earthquakes in this area have caused secondary hazards such as tsunamis and landslides that might have contributed to losses".

Indonesia experiences frequent quakes and volcanic eruptions due to its position on the Pacific "Ring of Fire", an arc of intense seismic activity where tectonic plates collide that stretches from Japan through Southeast Asia and across the Pacific basin.