A shallow undersea quake with magnitude of 5.9 jolted North Sumatra province on Saturday, the Meteorology and Geophysics Agency said here.
The quake, which struck at 4:39 p.m. Jakarta time, had an epicenter 91 km northwest of Nias Utara of the province at a depth of 10 km under sea bed, an official of the agency told Xinhua over phone.