A 6.1-magnitude earthquake struck off the coast of Indonesia's remote Maluku islands Thursday, the United States Geological Survey said, but no tsunami warning was issued. 

The strong quake hit at a relatively shallow depth of 31 kilometres (20 miles), about 127 kilometres southwest of the city of Ternate. 

Shallower quakes tend to cause more damage, but there were no immediate reports of casualties.

"It was a decent shake, but people weren't panicking," said Ternate resident Nasarudin Amin.

"There are warnings about potential aftershocks."

Indonesia experiences frequent quakes 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. 

In January, more than 100 people were killed and thousands left homeless by the 6.2-magnitude quake that struck Indonesia's Sulawesi island, reducing buildings to a tangled mass of twisted metal and chunks of concrete in the seaside city of Mamuju.

A powerful quake shook the island of Lombok in 2018 and several more tremors followed over the next couple of weeks, killing more than 550 people on the holiday island and neighbouring Sumbawa.

Later that year, a 7.5-magnitude quake and a subsequent tsunami in Palu on Sulawesi island left more than 4,300 people dead or missing.

In 2004, a devastating tremor measuring 9.1 magnitude struck off the coast of Sumatra and triggered a tsunami that killed 220,000 throughout the region, including about 170,000 in Indonesia.

The Boxing Day catastrophe was one of the deadliest natural disasters in recorded history, and lifted the ocean floor in some places by 15 metres.