Image copyright Getty Images Image caption Fatal attacks by bears are incredibly rare in Japan

Human flesh and hair have been found inside the stomach of a black bear shot dead in Japan after a series of deadly attacks, say local officials.

The bear is suspected of killing a 74-year-old woman whose badly mauled body was found on Friday near Kazuno in mountainous Akita prefecture.

Three men also died in apparent bear attacks in the area in recent weeks. All had been foraging for wild plants.

Locals have been warned to stay away from the area.

Police and firefighters are also mounting daily patrols in the mountains, encouraging anyone found to leave.

The female black bear was shot dead on Friday a short distance from the spot where the woman's body was found.

Hideki Abe, an Akita prefectural official, told AFP a "piece of human flesh" was found inside the bear's stomach when it was examined.

But he said it was not yet confirmed whether that particular bear was responsible for the woman's death.

"Two thirds of the stomach was filled with bamboo shoots," he said, which indicated that little human flesh was consumed by the bear, and that it may not have been alone in carrying out the attacks.

He said no bears had been captured in the traps set up in Kazuno city.

Many Japanese go into the mountains at this time of year to harvest bamboo shoots, which are also a staple food for bears.

Bear attacks on humans in the region are not unusual, but fatal ones are.

Only eight bear deaths have been counted from 1979 through to last year on Japan's main island of Honshu.