JAKARTA, Aug. 19 (Xinhua) -- A moderate earthquake with magnitude of 5.1 rocked Aceh province in northern tip of Sumatra Island on Tuesday, no report of damage or casualty, according to Indonesia's meteorology agency.

    The quake struck at 07:24 Jakarta time (0024 GMT) with epicenter at 64 km southwest Langsa town of the province and at 30 km in depth, an official of the agency said.

    Indonesia sits on a vulnerable quake-hit zone called "the Pacific Ring of Fore," where two continental plates meet that cause frequent seismic and volcanic movements.