Wild forest fires in northeast Japan have forced around 3,000 people to evacuate their homes as the flames move closer to residential areas.

Two forest fires in Iwate Prefecture were burning for a fourth consecutive day on Saturday, marking one of the worst mountain wildfire disasters in decades, according to the ministry of agriculture, forestry and fisheries.

The fires have scorched more than 730 hectares (1,800 acres) since breaking out on Wednesday afternoon in two districts of Otsuchi.

The first blaze engulfed a mountainous area, followed by another about two hours later, roughly 10km (6.2 miles) away, near residential neighbourhoods.

Pictures showed a large column of smoke rising up in the sky near the town of Otsuchi as helicopters dropped water on the burning forest. The fire could be smelled up to 30km away, residents have said.

The flames have advanced towards homes, destroying at least eight buildings. More than half of the town’s population of 3,233 is now under evacuation orders in Otsuchi.

More than 1,300 firefighters, along with troops from the Japan Self-Defence Forces, have been mobilised to battle the fires. Helicopters have also been deployed to drop water over affected areas and forests near homes at risk.

"Ultimately, I do hope it'll rain," a resident in Otsuchi told public broadcaster NHK.

Eight buildings, including one residence, have been engulfed in fire, officials said, but no casualties have been reported.

Experts say seasonal dry weather, combined with layers of dried fallen leaves on forest floors, is a recurring trigger for wildfires in parts of Japan each year.

Taken together, the current blazes have burned the third-largest area on record in the country, according to media reports – behind a 2025 wildfire in Ofunato that consumed about 3,370 hectares, and the Kushiro fire of 1992, which burned around 1,030 hectares. The Ofunato blaze early last year was the worst Japan had seen in more than half a century.

Scientists have long warned that climate change, driven by the burning of fossil fuels, will intensify and prolong periods of drought, creating conditions increasingly conducive to wildfires.