The man accused of planning the St Petersburg metro bombing has said he was following "instructions" and was an unwitting accomplice in the attack.

A lawyer for Abror Azimov, who was arrested on Sunday, said he had admitted to being behind the blasts, the BBC had reported. Russia's state-run TASS news agency had quoted a lawyer, Armen Zadoyan, as saying: "He admitted his guilt in full."

But at a preliminary court hearing Azimov said: "I did not realise that I was helping with this act. I was being given instructions," according to Reuters.

Earlier, a state investigator told the court that Azimov had confessed to having prepared the attack, but the suspect said he had not confessed to that.

The April 3 attack killed 14 people and injured more than 50.

Russia's Federal Security Service, as cited by RIA news agency, identified Azimov as having been born in 1990 and hailing from Central Asia.

He was the ninth person to have been detained on suspicion of having colluded with the bomber, Akbarzhon Jalilov, since the attack took place.

Azimov has been accused of training Jalilov to use the bomb, which he took with him on a train and detonated, killing himself in the explosion.