A shallow quake with magnitude of 6.6 struck waters off Bali Island, a center of Indonesia's tourist industry, on Friday morning, the Indonesian Meteorology and Geophysics Agency reported in Jakarta.

The U.S. Geological Survey first recorded the quake was at 5.9 magnitude and then revised it down at 5.7 magnitude.

The quake jolted at 1:43 a.m. Jakarta time Friday (1843 GMT Thursday) with epicenter at 210 km southwest Nusadua of Bali at the depth at 10 km under sea bed, an official of the agency Farid Nurahim told Xinhua over phone.

The agency did not issue tsunami warning as the quake magnitude was lower than 7, he said.

The intensity of the quake was felt at 3 to 4 MMI (Modified Mercally Intensity) at Karangkates of East Java, 3 MMI at Denpasar and Badung of Bali, and 2 MMI in Yogyakarta, he said.

Indonesia sits on a vulnerable quake-hit zone so called the "Pacific Ring of Fire."