Baku, July 30, AZERTAC Japanese Prime Minister Sanae Takaichi said Thursday that the death toll from the recent powerful earthquake in Kumamoto Prefecture has risen to 30, Xinhua reported.Speaking at a meeting of the government's emergency disaster management headquarters, Takaichi said the figure, as of 12:30 p.m. local time, included people whose deaths are still under investigation to determine whether they were directly related to the 7.1-magnitude tremor.An earthquake with a magnitude of 7.1 struck Kumamoto Prefecture at 4:27 p.m. local time on Tuesday. Authorities continue rescue and relief operations in the southwestern prefecture as they assess the extent of damage caused by Tuesday's earthquake.