India, July 28 -- A powerful earthquake measuring 7.1 on the Richter scale struck Japan's southern Kumamoto Prefecture on Tuesday, disrupting power supplies, halting train services and prompting tsunami and aftershock warnings.

An aftershock measuring up to a lower 5 on the Japanese seismic intensity scale struck the same area about 30 minutes later, prompting authorities to urge residents to remain alert for additional strong tremors, The Japan Times reported.

According to the newspaper, the earthquake's epicentre was located in the city of Uki, just south of Kumamoto City, at a depth of 10 kilometres.

Local media reported that several buildings collapsed near the epicentre, while the fire department said it received multiple emergenc...