A shallow undersea quake measuring 6.2 on the Richter scale rocked North Maluku in eastern parts of Indonesia on Tuesday, the Meteorology and Geophysics Agency reported here. The quake struck at 20:32 p.m. Jakarta time (1332 GMT) with epicenter at 30 km northeast Morotai Island of North Maluku and with a depth at 11 km under sea bed, an official of the agency told Xinhua over phone. Indonesia is prone to earthquake as it sits on a vulnerable quake-hit zone known as "the Pacific Ring of Fire."