JAKARTA, July 20 (Xinhua) -- An earthquake with magnitude of 5.6 rocked North Sumatra province of Indonesia on Sunday morning with no report of damage or casualties, meteorology agency said.

    The quake struck at 06:19 Jakarta time (2356 GMT Saturday) with epicenter at 155 km northwest Tanah Bala and at 10 kilometres in depth.

    Indonesia sits at a vulnerable zone so called "the Pacific Ring of Fire" where two continental plates meet that cause frequent volcanic movements.