JAKARTA, May 28 (Xinhua) -- A moderate earthquake measuring 5.1 richter scale jolted eastern parts of Indonesia on Wednesday evening, no initial report of damage or casualty, according to Indonesia's meteorology agency.

    The quake struck at 21:53 Jakarta time (1453 GMT) with epicenter at 170 km southwest Bitung town of North Sulawesi province and at 50 km in depth, an official of the agency said.

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