At least three people were killed by floods awash with volcanic mud in eastern Indonesia and thousands more displaced, an official said Wednesday.

Mount Gamalama, which forms the entire island of Ternate in the Maluku chain, erupted and spewed a column of ash about 2,000 metres (6,500) feet) into the air early this month, although there were no casualties or injuries then.

But two rivers on the eastern side of the 1,715-metre volcano overflowed Tuesday after heavy rains, carrying volcanic debris down to six villages, the Ternate disaster management agency said.

"Three people were killed in the lava mudflow and at least 2,561 villagers have been displaced. They are now being sheltered in several government offices," agency official Sukarjan Firto told AFP.

The Indonesian archipelago has dozens of active volcanoes and straddles major tectonic fault lines known as the "Ring of Fire" around the Pacific Ocean.

The country's most active volcano, Mount Merapi in central Java, killed more than 350 people in a series of violent eruptions last year.