Vladimir Putin has announced an intensification of attacks as revenge for the explosions in Belgorod, while emphasizing that Russia's targets are military, not civilian.
He added that "everything inside him is boiling".
This is reported by Currenttime.tv.
According to Russian authorities, the explosions in Belgorod resulted in the deaths of 24 people, including four children, and injured over 100.
The blasts occurred on Friday and Saturday, with Moscow accusing Ukraine of the attack.
On Monday, Putin met with soldiers in a Moscow hospital, in a conversation broadcasted by Kremlin's press services.
He repeatedly referred to the events in Belgorod, initially calling the attack an "act of terrorism."
He accused Ukrainians of firing rockets at the city center where civilians were present.
Putin stated that Russia could respond to Ukraine in the same way they attacked Belgorod.
He spoke about retaliatory attacks, noting that immediate counter-attacks were already being conducted, and more would follow.
Putin emphasized that no crime of this nature, particularly against civilians, would go unpunished and suggested that Ukraine's actions were intended to intimidate Russians.
He stressed Russia's commitment to intensify the attacks he had mentioned.