Authorities are searching for a bear that sneaked into the home of an elderly couple and raided their fridge amid concerns it may be behind 14 break-ins across a Japanese town in the past fortnight.

On Monday evening, Mitsuo Matsubara, 87, was confronted by a large Asiatic black bear when he went to investigate a noise in his kitchen. His fridge was open, and food was strewn across the floor. His wife called the police.

Break-ins have now been reported at five locations in the north-eastern town of Shizukuishi, leading officials to suspect one bear may be a repeat offender. They have set up box traps, installed electric fences around repeatedly targeted houses and deployed patrols to warn people about the bear.

“It’s unusual for a bear to break into the same place multiple times,” said Shiho Chida, a bear specialist with the nature division in Iwate prefecture, where the town lies. “It’s possible this is the same animal, so we want to capture it as soon as possible.”

So far, a bear has been caught breaking into buildings on a farm in the area four times over the past couple of weeks, helping itself to milk-based cattle feed. It was caught on camera attempting to open the sliding door of a farmhouse in the dead of night, but ran away after the farmer shone a light on it and shouted loudly.

In the hope of discouraging the unwanted intruder, the farmer has taken to spreading a homemade anti-bear mixture containing Japanese mustard around entranceways.

On Friday last week, another local resident came home from shopping to find a bear inside his house near the room where his elderly father was sleeping. The animal ran outside when he banged on a nearby door. But it attempted to come back inside, and the man spent about 30 seconds struggling to hold a sliding door shut as the bear stood on its hind legs trying to push its way in. He described the bear as about 1.65 metres tall.

The following evening a woman discovered a bear going through food in her kitchen, and on Sunday it broke into a Japanese confectionery shop and took doughnuts out of the fridge.

The bear’s sweet tooth has driven it to break into one house five times, where it has eaten cookies, sugar and karinto, a Japanese sugar-coated sweet made from fried dough.

Record numbers of bear attacks and fatalities have occurred in Japan in recent years. Experts believe that shrinking populations in rural areas have made it less intimidating for bears to come into towns, and that many have now lost their fear of humans.