Hundreds of rescue workers are battling for another day to reach possible survivors in the remains of the Aeon shopping mall in Kashima in the Kumamoto region.

Japan's earthquake death toll rises to 28, with survivors facing extreme heat and ongoing rescue efforts at a devastated mall.

Japanese emergency workers were battling to rescue any remaining survivors from a devastated shopping centre, as the death toll from a major earthquake hit 28 and thousands sweltered in punishing heat.

Soldiers and emergency workers combed through rubble looking for survivors Wednesday after an earthquake that killed at least 18 people, including a foreigner, in southwestern Japan.

Southwestern Japan suffered an earthquake of magnitude 7.1 on Tuesday, causing at least 18 fatalities and 62 injuries.

Japan's earthquake death toll rises to 28, with survivors facing extreme heat and ongoing rescue efforts at a devastated mall.