Yame(Japan) | Japanese Prime Minister Sanae Takaichi said 13 people have been found dead after a powerful quake shook part of southwestern Japan and rescue work was continuing Wednesday morning for the missing.

A magnitude 7.1 earthquake struck the Kumamoto area on the southern main island of Kyushu late Tuesday afternoon.

"There are people who are still waiting to be rescued, and it's a race against time," Takaichi said. "We will go all out to find and rescue as many people as we can." Takaichi offered her condolences to the victims and sympathy to their relatives, while urging those affected by the quake to take care of themselves under the hot weather.

Japan's Self Defence Forces joined rescue workers in the search and rescue operations at a badly damaged shopping mall and were delivering water, food and other necessities to the hard-hit areas, she said.

The quake collapsed the second floor of the Aeon Mall in Kashima Town, trapping people, according to the fire department in the prefectural capital of Kumamoto.

A chimney collapsed at the Nippon Paper Industries Co.'s Yatsushiro factory, trapping people under the debris, the Kumamoto emergency team said.

The affected area is about 900 kilometres (540 miles) southwest of Tokyo.

The Fire and Disaster Management Agency said major public facilities or infrastructure were not damaged, and the Nuclear Regulation Authority said no abnormalities were found at three nearby nuclear power plants.

Kyodo News said a hospital in the city of Yatsushiro took in about 40 people with injuries and about 50 others were taken to a hospital in Kumamoto city.

Many major manufacturers in Kyushu suspended operations Tuesday but found no major damage and planned to resume work Wednesday.

The runway at Aso Kumamoto Airport was closed, with no immediate word on when it would resume operations.

A train derailed and fell on its side at Yatsushiro station, and stone walls were damaged at Kumamoto Castle, a main tourist destination that was badly damaged in the 2016 quake and is still being repaired, Kyodo said.

"The shaking reminded me of the Kumamoto quake (10 years ago) and I was frightened," said Hiroki Shimoda, an official at Mifune town hall, who saw roof tiles of nearby homes crash to the ground. Kumamoto was hit with a deadly quake in 2016 that killed at least 50 people.

Shinji Kiyomoto with the Japan Meteorological Agency urged residents to be cautious over the next two to three days due to potential aftershocks.