Clashes between nationalists and riot police broke out into violent skirmishes after MPs backed reforms for more autonomy in the rebel-held east of the country. Of the 122 hospitalised, over 11 were in a critical condition, said Arsen Avakov, the Ukrainian Interior Minister.
Avakov said in a tweet that nearly 90 national guardsmen had been hurt, four of them with serious wounds to the eyes, stomach, neck and legs, by several explosive devices that were lobbed at them from crowds.
A 25-year-old national guardsman, who had been called up only in spring, had died of a gunshot wound in the heart, according to Anton Geraschenko, one of Avakov's advisers. However, this was denied by Avakov himself who said: "He died of splinters from grenades, not a gunshot wound."
A policeman's leg was torn off below the knee in the blast, according to Interfax Ukraine, and several journalists at the scene were also injured, according to a Reuters report.
Clashes between nationalists and riot police broke out into violent skirmishes after MPs backed reforms for more autonomy in the rebel-held east of the country. Petro Poroshenko, the Ukrainian president said the brutal conflict was a "stab in the back".
Demonstrators led by the Radical Party and the ultra-nationalist Svoboda (Freedom) party – who oppose any concession to the Russian-backed separatists – congregated outside the parliament building on Monday 31 August.
After a stormy debate, 265 MPs out of 450 backed the first reading of the decentralisation bill, giving further powers to Donetsk and Luhansk. At the boisterous session many voiced their disapproval by shouting "Shame!" The reforms are part of a peace plan to end fighting in eastern Ukraine.
Small explosions and a louder burst, believed to be a grenade, were heard by a BBC correspondent. "I saw some people - policemen and firemen - falling to the ground, and some running away from the site, limping. I saw pools of blood just near the wall of parliament," said Svyatoslav Khomenko from BBC News, Kiev.
Around 30 people have been detained, including a Svoboda member who is alleged to have confessed to throwing a grenade.
Almost 7,000 people have died since the conflict in eastern Ukraine broke out in March 2014, after Russia's annexation of the Ukrainian peninsula of Crimea.