ST. PETERSBURG, April 4. /TASS/. A suicide bomber theory of the St. Petersburg metro blast is yet to be confirmed by investigators, the Russian president’s press secretary Dmitry Peskov said late on Monday.

"It is in the competence of investigative agencies," he said when asked to comment on reports about possible involvement of a suicide bomber.

"The president has been informed about the preliminary results of the initial investigation," Peskov has added. 

According to the latest data, 11 people were killed and 45 hospitalized following the St. Petersburg metro blast.