A strong quake jolted North Sulawesi province of central Indonesia early today, an official of the meteorology and geophysics agency said. <br/><br/>The agency has revised the magnitude of the quake from 7.1 to 6.8 and a tsunami warning has been issued, Wahyu Kurniawan, official in charge at the agency said. <br/><br/>The quake struck at 03: 23 a.m. Jakarta time with epicenter at 246 km northwest km Sangihe Island and the depth at 48 kilometers under sea bed, he said.