An undersea earthquake registering 6.4 on the Richter scale struck the eastern Indonesian islands in North Maluku province Thursday morning, but there were no immediate reports of injury or damage, the Indonesian seismologist agency said, according to ANTARA. The quake struck at 8:22 am Jakarta time (0122 GMT) and its epicentre was about 216 kilometres north-east of Ternate, the provincial capital of North Maluku province, Indonesia's National Meteorology and Geophysics Agency was quoted by DPA as saying. The quake occured at about 105 kilometres below sea level. Indonesia, the world's largest archipelago nation, sits atop the Pacific Ocean's Ring of Fire, where the meeting of continental plates causes high volcanic and seismic activity.