Firefighters and army helicopters were battling a fire on Wednesday that has burned through a neighbourhood in southwestern Japan and forced more than 170 people to evacuate.

At least 170 homes have been damaged or burned down and a man in his 70s was unaccounted for, Japan's Fire and Disaster Management Agency said.

The fire started during strong winds on Tuesday evening near a fishing port in the city of Oita and spread to a forest.

Oita is on the southern main island of Kyushu.

Japanese television footage by midday showed smoke still rising from swaths of land filled with burned-down and damaged houses, though orange flames were no longer visible.

One resident told Kyodo News Agency she quickly fled without many of her belongings because the fire “spread in the blink of an eye.”

Dozens of fire engines and more than 200 firefighters were mobilised to battle the fire, which still was not fully under control nearly 20 hours after it started.

The Ground Self-Defence Force dispatched two UH1 army helicopters to join the firefighting effort.

Prime Minister Sanae Takaichi, in a statement she posted on X, offered her sympathy for those affected by the fire and pledged to “provide maximum support” for them. (AP)