JAKARTA, Indonesia -- A strong earthquake struck Monday in Indonesia's Banda Sea, but authorities said there is no tsunami threat.

The U.S. Geological Survey said the magnitude 7.3 quake was centred 208 kilometres (129 miles) below the earth's surface. It was felt in parts of Indonesia and in East Timor's capital Dili but there were no reports of damage.

Indonesia's geophysics agency said the deep quake didn't cause a tsunami.

The Banda Sea quake was recorded minutes after a 6.1 tremblor in a thinly populated area 233 kilometres (144 miles) west of Papua province's Abepura town, at a depth of 20 kilometres (12 miles).

Rahmat Triyono, Indonesia's head of earthquake and tsunami centre, said the Papua quake was followed by several smaller aftershocks, but there is no immediate report of major damage or injuries.

The large quake was felt across Australia's most northern city, Darwin, where many people evacuated high-rise buildings.

Office workers were seen throughout Darwin outside buildings after the quake rattled the city for around five minutes.

One worker, who gave her name only as Robyn, said no alarm had gone off but workers had decided to get out of her building anyway.

She said it was the strongest quake she had ever felt in Darwin.

There was no damage or injuries reported in Darwin.

Indonesia is prone to earthquakes and volcanic eruptions due to its location along the Pacific "Ring of Fire." A powerful Indian Ocean quake and tsunami in 2004 killed a total of 230,000 people in a dozen countries, most of them in Indonesia.