People including relatives of victims of the Monday's metro bombing attend a memorial service at the Trinity Cathedral in St.Petersburg, Russia, April 5, 2017. REUTERS/Anton Vaganov

MOSCOW (Reuters) - Russia’s Federal Security Service has identified the person who orchestrated an attack that killed 14 people on the St. Petersburg metro earlier this month, Russian news agencies reported on Thursday, citing FSB chief Alexander Bortnikov.

“He has been provisionally identified. Yes, yes, identified,” agencies cited Bortnikov as saying.

Police have so far detained 10 people they suspect of being involved in the attack.