A powerful 7.1-magnitude earthquake struck Kumamoto Prefecture on Japan's southern island of Kyushu on Tuesday afternoon, triggering emergency warnings and prompting authorities to assess the extent of the damage.

Japan's public broadcaster, NHK, reported that "many people" were trapped inside an Aeon shopping mall damaged by the earthquake. Earlier, local police reported an explosion at the mall in Kashima Town.

Japan's public broadcaster NHK reported that at least two women were killed in the mall.

They were among eight people rescuers managed to take out of the building. A third person was reported to be in cardiopulmonary arrest, while the five others' condition was not life-threatening.

NHK had initially reported that at least 50 people were hospitalized after the earthquake.