FEARS are growing for a group of ten tourists who vanished while hiking on a bear-infested island.

The hikers – nine women and a man – have now been missing for two nights on Iturup island in Russia’s Far East.

The group had set out on an 11-day trek to summit the 3,714ft Baransky volcano, which remains an “active” threat.

Guide Valery Fedosov, 36, from St. Petersburg, briefed the group, though the tourists apparently didn’t notify the authorities about their journey in advance.

The Russian hikers “stopped communicating” on Saturday night, raising alarm bells.

Before embarking on the hike, the group were given clear instructions from Fedosov about the threat of brown bears on the island.

The safety instructions state: “On our hike, our best allies are making noise, being in a large group, and using all the appropriate gear to scare off bears, which the guides will carry.”

“Good news – the probability of meeting bears on our route is very low.

“In four years of hiking, we have met them only three times, and then from afar.”

An estimated 600 wild bears roam Iturup island, whose ownership remains a point of dispute between Russia and Japan.

The island – about the size of Cornwall – is home to an active volcano that last erupted in 1951 and has also experienced hydrothermal explosions.

It’s notorious for its thick fog, which has made rescue efforts challenging.

The remote island is also said to have patchy communication services.

The group failed to catch a bus scheduled for Saturday evening after their climb.

By midnight Sunday, they still hadn’t been located.

Local official Marina Kuzmina said: “They did not come to the [meeting] point, the guide waited for them there for about six hours.”

She added: “The group consists of 10 people – nine women and one man, the escort.”

Among the tourists who are unaccounted for are Dr. Ekaterina Kaynova, 32, a surgeon; Dr. Irina Tyulkina, a beauty therapist; Regina Belal, 33, a university research fellow; and Polina Podolyako, 29, a housing manager.

Officials are furious that the guide did not inform authorities about the trip.

The head of the Kuril islands, Konstantin Istomin, has taken the search into his “personal control”.

“Rescuers, interior ministry officers and a representative of the district administration have been brought in to conduct the search,” he said.

The Sakhalin Region Investigative Committee has initiated a criminal investigation to check if the group violated any regulations and to explore suspicions about the guide, possibly having no prior knowledge of the area.

Meanwhile, the guide’s wife, Anastasia, was reported to be on the tour, but she’s not listed as missing.

Another tourist, who had medical issues, stayed behind at the base camp and was later taken to hospital.