A strong earthquake has shaken Indonesia. The authorities have since issued a tsunami warning. More aftershocks are possible.

A major earthquake hit Indonesia on Monday. According to the USGS the earthquake was of magnitude 7.6. The Indonesian authority BMKG estimated the strength at 7.9. Some spoke on social media of the worst shocks in decades. The tremor lasted about two minutes. Information on damage or injuries was not initially available.

At first, there was a tsunami warning but feared waves on the coasts did not materialize according to the first reports. The tremors were felt as far away as Australia.

The quake happened early Tuesday morning (local time). The epicenter was about 217 miles northeast of East Timor in the sea. According to the U.S. earthquake observatory, the source was around 59 miles below the sea floor. That's relatively deep. The earthquakes with the greatest destruction usually happen much closer to the surface.

Indonesia lies on what is known as the "Pacific Ring of Fire," an arch in the Pacific Ocean where tectonic plates meet. There are numerous volcanoes. There are frequent earthquakes there.

The sea floor in the South Pacific east of Australia had already trembled on Sunday. The U.S. earthquake monitor USGS located the quake around 14 miles northwest of Port Orly in the island state of Vanuatu at a depth of 17 miles. Weaker aftershocks followed later.

The US agency NOAA had briefly warned of a possible threat of tsunami waves in nearby waters.