An earthquake with magnitude of 5. 3 jolted the Sumatra island of Indonesia Sunday evening, the country\'s Meteorology and Geophysics Agency reported. The quake struck at 21:21 p.m. Jakarta time (14:21 GMT) with epicenter at 100 km southwest Tanggamus of Lampung province and with the depth at 10 km under the sea, an official of the agency told Xinhua by phone. Indonesia sits on a vulnerable quake-hit zone so is known as \" the Pacific Ring of Fire.\"