The quake hit at a depth of 208 kilometres (129 miles) south of Ambon island in the Banda Sea at 11:53 local time, the US Geological Survey (USGS) said. The Pacific Tsunami Warning Center said the quake was too deep to trigger a destructive wave.
There were no reports of casualties or any damage after the quake hit.
Indonesia warns of further eruptions after volcano spews ash
Indonesia's disaster agency said the tremor was felt in faraway Bali, while residents of the northern Australian city of Darwin also felt it.
The city evacuated parts of its central business district after the quake struck, the Australian Broadcasting Corporation reported.
Australia lies south of Indonesia, the world's biggest archipelago nation, which is regularly struck by quakes.
"Wow, that was quite an impact for #Darwin, hope everyone is safe," the bureau of meteorology in Australia's Northern Territory said on Twitter.
Earlier Monday, Indonesia's Papua province was hit by a 6.1-magnitude earthquake, about 240 kilometres (150 miles) west of the town of Abepura, at a relatively shallow depth of 21 kilometres, according to the USGS.
There were no immediate reports of casualties after that quake.
A shallower 6.3-magnitude tremor hit the area last week, but the damage was not extensive.
Bali volcano spews ash in new eruption
Indonesia experiences frequent seismic and volcanic activity due to its position on the Pacific "Ring of Fire", where tectonic plates collide.
Last year, a 7.5-magnitude quake and a subsequent tsunami in Palu on Sulawesi island killed more than 2,200 with a thousand more declared missing.
On December 26, 2004, a 9.1-magnitude earthquake struck Aceh province, causing a tsunami and killing more than 170,000.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ