JAKARTA : A strong 5.9-magnitude aftershock rocked an eastern Indonesian province on Thursday, one day after a 6.6-magnitude quake prompted a brief tsunami alert, the meteorology and geophysics office said.

The aftershock struck at 10:41 am (0141 GMT) and was centred 248 kilometres (154 miles) northwest of Saumlaki town in Maluku province, the office said in a statement.

There was no risk of a tsunami, the office said.

Indonesia sits on the Pacific "Ring of Fire" where continental plates meet, causing frequent seismic and volcanic activity.

The archipelagic nation was hardest hit by the earthquake-triggered Asian tsunami in December 2004 which killed an estimated 168,000 people in Indonesia's Aceh province. - AFP/ch