TOKYO (Kyodo) -- Services on the Kyushu Shinkansen bullet train line will remain halted Wednesday, its operator said, a day after an earthquake with a magnitude of 7.1 struck the southwestern Japan prefecture of Kumamoto.

Meanwhile, trams will resume operation at reduced speeds in the city of Kumamoto, according to the Kumamoto City Transportation Bureau, which warned that services could be suspended in the event of another strong earthquake.

The weather agency urged the public to remain on alert for further quakes.

Railway, road and air transportation systems in the prefecture have been disrupted since Tuesday's temblor, which registered a maximum 7 on the Japanese seismic intensity scale.

After the quake, an explosion rocked a shopping mall in Kumamoto operated by the Aeon group, with rescuers searching for the missing. Local authorities said Wednesday that two women were confirmed dead and a woman was found unresponsive.

Around 200 people were able to evacuate from the mall before the explosion and collapse of its second floor, the authorities said.