VOLGOGRAD, November 7 (Itar-Tass) - Investigators have questioned more than 150 witnesses in the on-going probe into the terrorist attack in Volgograd, in which six people were killed," head of the regional department of the Investigative Committee /SK/ Mikhail Muzrayev told reporters on Thursday.
Terrorists began preparations for the attack on September 10, 2013, Muzrayev added. The yield of the bomb containing destructive agents such as metal fragments, made up 500 to 600 grams of TNT.
Specialists believe that suicide bomber Naida Asiyalova set off the explosive device on her own. Her boyfriend Dmitry Sokolov, 21, though reported missing, is supposedly staying in Dagestan. Police are looking for him.
"Sokolov got acquainted with Asiyalova three years ago. Both were followers of radical Islam which brought them together," the SK official said.
Sokolov might be involved in the Volgograd terrorist attack. He regularly visited mosques when he lived in Moscow, and established contacts with extremists. Police have information that Sokolov was a demolition expert of the Makhachkalinskaya terrorist group. His Muslim name is Abdulzhabar nicknamed Zhiraf.
As for Naida Asiyalova, the investigators found that she had had serious health problems. "The medical records retrieved during the search at her room showed that she suffered from a kidney disease and other serious illnesses. Cumulatively, she must have felt terrible pain which probably was one of the causes behind her decision to blow herself up," Mizrayev said.
Russian Investigative Committee spokesman Vladimir Markin earlier said the investigators had a detailed picture of Asiyalova's last hours of life.
"Asiyalova, who was wearing a hijab, went on foot along busy streets in the Dzerzhinsky and Sovetsky districts, including in the area of the Akvarel mall. It was in that area that she boarded bus 29 where she later blew herself up, the SK spokesman said.
Meanwhile, Muzrayev said he was bewildered at biased media reports with absurd versions of the explosion, which undermined the image of law-enforcement bodies.
At around 14:00, Moscow time, on October 21, suicide bomber Naida Asiyalova blew herself up on a bus in Volgograd, killing six and injuring another 40 passengers. Seventeen victims are still being treated in Volgograd hospitals, and another seven in Moscow hospitals.