It was the worst unrest in the Ukrainian capital since a bloody uprising ousted Moscow-backed president Viktor Yanukovych in early 2014, unleashing a separatist insurgency in the industrial east.
The clashes erupted yesterday when hundreds gathered outside the parliament to protest after legislators gave initial backing to a bill granting a degree of autonomy to Kremlin-backed rebels in eastern Ukraine.
The government blamed ultra-nationalists for the unrest, saying they detonated a live grenade near the entrance to the parliament building.
"We have already found the perpetrators," pro-Western President Petro Poroshenko said in a televised interview today.
"The organisers, who were distributing baseball bats, who helped bring weapons, will also be found."
Poroshenko, who was to visit the wounded later on Tuesday, branded the violence a "stab in the back" saying the perpetrators deserved "severe" punishment.
A member of the National Guard died on the operating table Monday, killed when a grenade fragment reached his heart.
More than 140 people were being treated in hospital, officials said.
"According to our latest data, 141 injured people remain in hospitals all over Kiev," police spokeswoman Oksana Blyshchyk told AFP.
