A 6.8-magnitude earthquake struck off Indonesia's eastern province of North Maluku this morning, but did not cause casualties or damages, authorities said.

The earthquake occurred at 3.02am local time with its epicentre located 133km northwest of Morotai Island district and a depth of 112km under the seabed, and did not trigger a tsunami, the country's meteorology, climatology and geophysics agency said.

The tremors of the earthquake were also felt in the nearby province of North Sulawesi, according to the agency.

So far, the tremors of the quake did not cause damage to buildings or infrastructure facilities, said Abdul Muhari, spokesperson of the National Disaster Management and Mitigation Agency.

"There are no initial reports of damages or casualties after the earthquake," he told Xinhua via phone.

"The residents in the Morotai Island district felt the tremors, but did not panic," Yusri A Kasim, head of the emergency unit of the disaster agency in North Maluku province, said.

Indonesia sits on a vulnerable quake-hit zone called "the Pacific Ring of Fire".

- Bernama