Jakarta, Indonesia: A 6.0-magnitude earthquake struck off the coast of Indonesia's Java island Saturday, the United States Geological Survey said, but no tsunami warning was issued.

The quake hit at a depth of 82 kilometres (50 miles), about 45 kilometres southwest of Malang city in East Java.

There were no immediate reports of casualties, but the temblor shook Malang, a city of several million people.

"It was pretty strong and went for a long time," resident Ida Magfiroh told AFP.

"Everything was swaying."

Indonesia experiences frequent seismic and volcanic activity due to its position on the Pacific "Ring of Fire", where tectonic plates collide.

In 2018, a 7.5-magnitude quake and a subsequent tsunami in Palu on Sulawesi island left more than 4,300 people dead or missing.

On December 26, 2004, a devastating 9.1-magnitude earthquake struck off the coast of Sumatra and triggered a tsunami that killed 220,000 throughout the region, including around 170,000 in Indonesia.

It was one of the deadliest natural disasters in recorded history.