Russian charged over sub disaster

The K-152 Nerpa was carrying many more people than usual

A sailor has been charged for setting off a firefighting system on a Russian nuclear submarine that released gas, killing 20 people, investigators say.

They say the suspect - who has not been named - activated the system "without authorisation and for no reason".

They say the man "has already admitted his error", but some officials have cast doubt on the announcement.

Twenty people, mostly civilians, died when freon gas was released on the Nerpa attack submarine on Saturday.

In all, three servicemen and 17 civilians were killed and another 21 people were injured during sea trials in the Sea of Japan.

'Scapegoat'

"The suspect faces charges of negligence for causing the deaths of two or more people," said Vladimir Markin, representative of the prosecutor general's office.

I was lying down resting after being on watch. Suddenly the freon gas started coming down right above me. It was like a drug. I lost consciousness Viktor Rifk, survivor

However, Mr Markin declined to give any details about the accident.

If found guilty, the sailor could be jailed for seven years.

But a member of Russia's Public Chamber, which oversees the government and parliament, expressed concern about the speed with which the investigators announced that they had found the culprit.

Anatoly Kucherena said the law stipulated there should be a thorough investigation and collection of evidence followed by a trial in court at which any suspects would be found either guilty or innocent.

Several defence experts have also expressed fears that the sailor might be a scapegoat, and one member of the Nerpa's crew was quoted by Russia's Interfax news agency as saying that his colleague could have made a confession under pressure.

The Nerpa, or Akula-class, submarine had more than 200 people aboard, 81 of them service personnel, when the accident happened.

On Wednesday, officials said that preliminary investigations suggested that the "unsanctioned activation" of the automatic firefighting system caused the tragedy.

Freon gas displaces oxygen from the air to put out a fire.

There has been speculation that overcrowding and the presence of so many civilians aboard the vessel may have contributed to the death toll - but this has not been confirmed by the investigators.

Survivor's account

Several survivors later recalled the terrifying seconds after the gas started filling some sections of the submarine.

Viktor Rifk said he managed to put a gas mask on time

"I was lying down resting after being on watch. Suddenly the freon gas started coming down right above me. It was like a drug. I lost consciousness," said Viktor Rifk, an engineer, quoted by the Komsomolskaya Pravda newspaper on Tuesday.

"We all had gas masks but maybe some people didn't manage to put them on in time," Mr Rifk later told Russia's NTV television.

A number of the people were sleeping when the accident happened, and reports in Russian media suggested that some of them were too dazed to put on gas masks.

Several former Russian mariners have suggested that the civilian personnel - engineers and shipyard workers - may have lacked experience in handling the breathing apparatus.

The nuclear reactor, which is in the stern, was not affected and there was no radiation leak, officials said.

Russia's worst submarine disaster happened in August 2000, when the nuclear-powered Kursk sank in the Barents Sea. All 118 people on board died.

The then president, Vladimir Putin, was criticised for being slow to react to the incident and reluctant to call in foreign assistance.