A powerful 7.1-magnitude earthquake struck Japan's southern Kumamoto Prefecture on Tuesday, injuring at least 50 people, damaging buildings and roads, and forcing hundreds of thousands of residents to evacuate.

According to Japanese authorities, the earthquake's epicentre was located around 20 kilometres south of Kumamoto, the largest city on Kyushu island with a population of about 700,000.

The quake knocked out power to thousands of homes, ruptured roads and caused widespread structural damage across the region. Several people were reported trapped inside a partially collapsed shopping mall, while multiple buildings, including an Aeon shopping mall, sustained significant damage.

A blast following the earthquake caused extensive destruction at the shopping complex. A spokesperson for Aeon did not immediately comment on the incident.

Aerial footage released by Japan's Ministry of Defence showed thick smoke rising from quake-hit areas in southern Japan as emergency response teams rushed to affected locations.

The government issued emergency earthquake warnings for Kumamoto, Nagasaki, Kagoshima, Fukuoka, Saga, Oita and Miyazaki prefectures across Kyushu. Authorities also instructed around 300,000 people to move to evacuation centres as a precaution.

The Japan Meteorological Agency briefly issued a tsunami warning for waves of up to one metre but later lifted the alert after assessing the threat.

Officials have warned residents in the worst-hit areas to remain vigilant, saying strong aftershocks could continue for about a week. They also cautioned that unstable ground conditions could increase the risk of landslides.

Japan, located along the seismically active Pacific Ring of Fire, experiences some of the world's most powerful earthquakes and accounts for around 20 per cent of global earthquakes measuring magnitude 6.0 or higher.

The latest quake comes a decade after Kumamoto was devastated by a series of earthquakes that killed 275 people and injured more than 2,700, making it one of the country's deadliest natural disasters in recent history.