A "BLACK Widow" suicide bomber who planned to detonate explosives in central Moscow was killed when a spam text message from her mobile-phone company set off the device early.

News of the botched New Year's Eve operation emerged yesterday as Russian security sources said they had identified the suicide bomber who killed 35 people at a Moscow airport last week.

He was a 20-year-old man from the North Caucasus, a spokesman for the national investigative committee said.

It was also revealed that the explosive belt the man was wearing had been remotely activated. Terror attacks in Russia have ramped up during recent years, with suicide bombings becoming more common.

The "Black Widow" bomber, who has not been named, had intended to detonate the explosives in a busy square on January 31.

But a spam message wishing her a happy new year caused it to go off earlier than planned, instantly killing her but not harming others, security sources said.

The woman had been at a safe house in Moscow with two other bombers when the device exploded.

Mobile phones are often used as detonators by Islamist terrorist groups in Russia.

A "handler" who watches the bomber as they move into the target area sends them a text message to detonate the explosives.

The phones, which have not been previously used, are usually kept turned off until the last minute.

The woman's handler has been named as Zeinat Suyunova, 24, whose husband is in prison for being a member of a radical Islamist terror group.

Security services believe the failed bomber may have been part of the group that targeted Moscow's Domodedovo airport last Monday.

Thirty-five people were killed and hundreds injured when explosives were detonated in the baggage hall.

Both groups of bombers may have been part of a squad that was trained at al-Qaeda camps in Pakistan.

Immediately after the airport attack, investigators blamed militant Islamist groups from the North Caucasus, which includes the republics of Chechnya and Dagestan.

For more than a decade, radical Islamic groups have been fighting for an independent "emirate" in the North Caucasus, a region that has long been plagued by poverty and high unemployment.

Russian President Dmitry Medvedev has ordered Premier Vladimir Putin to put forward proposals for improved security on public transport throughout Russia.