Chechen rebels have been blamed for a suspected suicide bomb attack on a Russian train today that killed at least 40 people and wounded dozens.
The explosion happened on a commuter train near the war-torn region of Chechnya. Major General Nikolai Lityuk of the Emergency Situations Ministry said the bomb went off inside the train's second carriage.
Russian President Vladimir Putin said the bomb attack was "an attempt to destabilise the country on the eve of parliamentary elections.
"The criminals will get nothing out of this," he was quoted as saying at a meeting with top security officials.
Russian Justice Minister Yuri Chaika said it was possible Chechens guerrillas were responsible.
"I connect this criminal act, if we are to believe one of the versions, with the activities of Chechen terrorists, aimed at demoralising people and destablising the situation on the eve of elections to the State Duma," Mr Chaika was quoted as saying.
A spokesman for the prosecutor's office in the region of the explosion, said authorities were treating the attack as an act of terrorism. It is believed the attack was carried out by a male suicide bomber and a number of women, some of whom were seen jumping from the train shortly before the blast.
The bomb went off at around 8 a.m., in a rush-hour attack that seemed calculated to kill and injure a maximum number of people. The train was travelling between the cities of Mineralnye Vody and Essentuki.
The force of the explosion toppled the second car on to its side and fire fighters and ambulance workers struggled to pull victims from the mounds of shattered glass in the wreckage. A small fire broke out in the electrical wiring in the wreckage, hampering rescue efforts.
Hours after the blast, rescue workers continued to pull dead from underneath the wreckage. Six people were killed in two blasts on the same train line in September.
No group claimed responsibility for those attacks.
Russia has been hit recently by numerous bombings and suicide attacks, which the government usually blames on rebels from Chechnya.