Missing plane mystery in Russia

Police and rescue teams in Russia have been left bewildered after an aeroplane carrying 13 people took off under mysterious circumstances from a regional airfield more than a month ago and disappeared without trace.

Rescue aircraft and teams on foot have covered more than 275,000 square kilometres in search of the AN-2 biplane

Up to 2,000 volunteers and emergency officials and 14 aircraft have been searching at any one time for the AN-2 biplane, which flew without permission from a runway in Serov near Yekaterinburg, in the Urals, at 11pm on June 11.

Relatives of the missing passengers have been left hoping that their loved ones survived a crash and are perhaps alive in a desolate wilderness, like the heroes of the American TV series, Lost.

A senior policeman in the region, Valery Gorelykh, told reporters after the disappearance that the group had set off on their unscheduled flight after a drinking session. He said one theory was that they intended "to go fishing or to a bathhouse". Thrashing oneself with birch twigs in – sometimes remotely located – steam saunas is a popular Russian pastime.

The rescue operation has been hampered because part of the region is hilly and covered in the dense forest known as "taiga". At least 25 rescuers have received potentially dangerous tick bites and one almost drowned in a swamp.

The plane's pilot, the chief traffic policeman of Serov and another officer, a security guard and the airfield's nightwatchman – who was reportedly wearing slippers – were among those who got on board, along with some of the men's relatives, including at least two women.

Rescue aircraft and teams on foot have covered more than 275,000 square kilometres in search of wreckage or survivors.

On Wednesday, Andrei Zalensky, head of the regional emergencies ministry, said it was possible the missing had not perished. "Even if some of them are injured they could survive, but they won't be able get out on their own. We must continue to search." Last week, the families of four of the missing people wrote to Vladimir Putin, Russia's president, asking him to beef up the search effort with more professional rescue units.

The AN-2 is owned by a local company, Avi Zov, and had been employed to fight forest fires. A mechanic working at the airfield from which it left said he had witnessed the take-off and tried to stop the pilot, Khatim Kashapov, from flying.

Attempts to find the plane continued on Tuesday. The mystery surrounding its disappearance has prompted local media to recall the infamous Dyatlov Pass incident, in which nine ski hikers perished in odd circumstances in the northern Urals in 1959. When their bodies were discovered, two victims had cracked skulls, two had broken ribs and one had her tongue missing, although there were no signs of struggle at the scene.

A Soviet investigation concluded the team died as the result of "a compelling unknown force".

Psychics, intrigued by the new mystery, have rushed to offer their help in locating the plane, but Mr Zalensky said their efforts were in vain. "If I marked on a map every point suggested by a psychic and joined them up I would have a flower 500km across," he said.