Russia’s Investigative Committee says it has indicted the suspect in the St. Petersburg supermarket bombing earlier this week on terrorism charges.

In a statement on December 31, the committee said the suspect -- Dmitry Lukyanenko -- “deliberately made and planted a homemade explosive device” used in the December 27 attack that left 13 people injured.

Lukyanenko told investigators that he had been motivated by “hatred toward the organizers and participants” of mind-set training sessions that he had attended, the committee said without disclosing further details.

According to the committee, Lukyanenko left two USB drives near the site of the blast with information about his actions and photos of the explosive device.

The statement said Lukyanenko had been monitored by mental health professionals since he was 19 for undisclosed issues. It did not say how old he is now.

The Islamic State extremist group claimed responsibility for the blast but did not provide evidence to support the claim.

The claim came after Russian President Vladimir Putin said the explosion was an act of terrorism.

A day after the blast, Putin told security forces to “take no prisoners” when handling imminent threats from terror-plot suspects.

Investigative Committee spokeswoman Svetlana Petrenko said on December 27 that the "homemade bomb" that ripped through a customer locker area at a Perekryostok supermarket exploded with the power equivalent to 200 grams of TNT.

Based on reporting by Reuters and meduza.io