A former paramedic who converted to Islam and joined a militant cell could be the Volgograd train station suicide bomber according to investigators. The new prime suspect has been identified as Pavel Pechyonkin, and not 26-year-old woman Oksana Aslanova as was previously believed. Police now think that Pechonkin, who left to join Dagestani militants in 2011, carried out the devastating attack which killed 17 people on Sunday. The Muslim convert posted a video on Youtube saying that he was following God's will, that he would not turn back and that he working to earn a place in heaven. His video was in response to a message from his parents Nikolai and Fanaziya, begging him not to use violence and described their lives as 'hell' without him. A medical school graduate, his father Nikolai spoke about his conversion: 'My son changed for the better. He stopped arguing with me, did not drink, went to the mosque. I bought him Halal meat.' Then following a visit to Moscow, he vanished six months ago. His parents heard he had gone 'in the forest' with rebels and made an internet appeal for him to return. 'Pasha, come back, let your hands be on blood from wounds, injuries, and not from kills, you're a doctor,' said his father. He replied about his parents' video appeal: 'It was sad to see your tears, very sad. I didn't even want to watch. I thought it would weaken me. I came here so Allah would be pleased with me, to earn my way to paradise.' His parents travelled to Dagestan, hoping to find their son and rescue him from the militants they believe indoctrinated him. The Moscow Times reported that his mother said: 'Imagine that somebody were to kill your parents, how would that make you feel? Why are you turning children into orphans?' Pechyonkin told his parents that he had then decided he would not be swayed. He said: 'I didn't want to watch your appeal, I thought that it would weaken me, that it would make me softer.' He added: 'Why should we follow those Christian commandments, when Allah, may he be glorified, urges us to fight those kafirs [unbelievers]. 'Why shouldn't we leave their children orphaned?' It is believed that investigators will take DNA from Pechyonkin's father to see if it is a match to tissue found at the scene. 17 people are known to have died in the blast, with more than 50 left injured. Witness Alexander Koblyakov said: 'People were lying on the ground, screaming and asking for help. I helped carry out a police officer whose head and face were covered in blood. He couldn't speak.' Vladimir Markin, a spokesman for Russia's Investigative Committee, said: 'A suicide bomber who was approaching a metal detector saw a law enforcement official and, after growing nervous, set off an explosive device.' More than 40 people were reported as injured and the death toll could rise, according to Russian officials. The attacker was originally named as Oksana Aslanova, who had twice married separatist Muslim gang leaders from the troubled Caucasus region, sources said. She had been on Russia's wanted list for 18 months before the attack which used 16lb of TNT, the deadliest in Russia for three years. The bomb was the equivalent to at least 10kg of TNT, said to Committee spokesman Vladimir Markin, and was stuffed with metal shrapnel. President Vladimir Putin has reportedly instructed special flights to be laid on to airlift the injured to Moscow clinics if necessary. Metal detectors have been mandatory in railway stations and airports throughout Russia since a suicide bomber killed 37 people at Domodedovo airport in 2011. Footage from a CCTV camera facing the station showed the moment the bomb went off, with a bright orange flash emerging from inside the station followed by billowing smoke. 'Someone tried to get inside the train station but was not allowed in,' an unidentified law enforcement official told Vysota 102, a local news agency. 'After that an explosion went off.' Among the dead was a police officer checking people entering the train station and a child, The Moscow Times reports. Local media reports claim taxi drivers queuing for customers outside the station were the first respondents to the emergency. Volgograd mayor, Irina Guseva said the drivers were able to save lives by taking injured victims to hospital before ambulances arrived at the scene. The attack comes months after Chechen rebel leader Doku Umarov called for new attacks against civilian targets in Russia, including the 2014 Games which will take place in Sochi.