TOKYO -- Two women were killed and one person was left in cardiac arrest following an explosion at a shopping mall in Japan's southwestern Kumamoto Prefecture after a powerful earthquake struck the region, local media reported early Wednesday.

According to the Kumamoto prefectural government, eight people had been rescued from inside AEON Mall Kumamoto, a major shopping complex in Kashima Town in the region by 4:00 am local time Wednesday (1900 GMT Tuesday), public broadcaster NHK reported.

Among them, two women in their 20s were confirmed dead, while another person was found in cardiac arrest. Five others sustained injuries but are not believed to be in life-threatening condition, the report said.

Authorities suspect the explosion may have been caused by a gas leak triggered by the earthquake, although the exact cause remains under investigation.

The magnitude-7.1 quake struck Kumamoto Prefecture at 4:27 pm local time Tuesday (1927 GMT) at a depth of about 10 km, according to the Japan Meteorological Agency.