A Russian priest who specialises in the Apocalypse has been trying to coax members of a Doomsday cult to come out of a cave where they have spent five months waiting for the world to end.

Thirty-five members of the True Russian Orthodox Church, mainly women and children, have been barricaded in the underground bunker in a windswept ravine near the river Volga for most of the winter, after their leader told them that the Apocalypse foretold in the Book of Revelation was due to happen in May.

Fears have grown for their safety since part of the entrance to the cave collapsed last week. Seven members of the group emerged on Friday, but the rest - including at least one child under the age of two - are still refusing to leave and have threatened to blow themselves up with 100 gallons of petrol stockpiled in canisters if the authorities try to force them out. Last week they were reported to have shot at police to drive them away.

Oleg Melnichenko, the deputy governor of the Penza region which lies 300 miles southeast of Moscow, told the Interfax news agency that he had called in Father Hermogen in a fresh attempt to reason with the sect.

"He is a specialist in the Book of Revelation," said Mr Melnichenko. Father Hermogen has been speaking to the group down a ventilation shaft, but so far there is no word whether is having any success.

The True Russian Orthodox Church was founded by Pyotr Kutnetsov, a 43-year-old engineer and self-declared prophet who forbids his followers from watching television, listening to the radio or handling money. They believe that credit cards and the barcodes on food packaging are Satanic.

Mr Kutnetsov set up the cult several years ago after splitting from the mainstream Russian Orthodox Church, recruiting his followers by writing books and touring monasteries in Russia and Belarus. He has told the group that when they die they will be allowed to judge whether others should go to heaven or hell.

Mr Kutnetsov ordered his followers to burn their passports and go into the cave last November, but did not accompany them himself, saying that God had given him different tasks.

Pravda reports that soon after he was arrested by the authorities and charged with setting up a religious organisation associated with violence. After a mental health evaluation however psychiatrists said that he was unfit to stand trial.

The authorities have kept in regular contact with the cultists, who agreed to accept food so long as it had not been processed with modern factory equipment. Last week they were reported to be asking for a cow, so that they could enjoy fresh milk that had not been processed.

The authorities have made repeated efforts to persuade the cultists out, sending doctors, rescue workers and Russian monks scrambling down the heavily wooded ravine, which lies near the village of Nikolskoye.

Local residents said that the bunker was a pre-revolutionary convent with a well, a kitchen and areas for sleeping and praying.

On Friday the entrance to the bunker partially collapsed after rain and melting snow soaked the muddy hillside and the ground gave way. Seven women were isolated from the rest of the group by the mudslide, and had to emerge from their shelter and seek refuge in a nearby home. The rest of the group remains barricaded in.

“In as much as their beliefs have been formed over a long period of time, convincing them to come out is not going to happen quickly,” said Alexander Yelatontsev, a spokesman for the Penza regional authorities.

Georgy Ryabov, a Russian Orthodox Church spokesman, said that the emergence of Mr Kuznetsov's cult was a consequence of "the absence of a system of spiritual and moral education" in Russia.

"All Christians of Russia have to pray for them so they awaken and understand their mistake," Mr Ryabov said.