JAKARTA - An earthquake measuring 5.3 on the Richter scale struck off North Sumatra of Indonesia earlier Thursday, the Indonesian Meteorology and Geophysics Agency reported.

The quake struck at 07:41 am Jakarta time (00:41 GMT) with epicenter at 25 km southeast Sibolga of North Sumatra and with the depth at 64 km under the sea bed, an official of the agency told Xinhua over the phone.

An earthquake 5.6-magnitude was reported by the agency that hit West Sumatra at 05:12 am Thursday.

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