A grenade exploded outside Ukraine’s parliament as lawmakers backed giving more autonomy to rebel-held areas.
Two people have died and more than 90 others were injured in the violence which has been blamed on the country’s main nationalist party.
One man has been arrested and 30 others detained.
Angry opponents of the bill which gives certain self-management rights to separatists controlling parts of Donetsk and Luhansk regions, say it plays into Russia’s hands and will lead to Ukraine losing control in the east.
They also object to the separate legislation on local self-governance which they fear will give the separatists the right to form their own courts and militia and create a special relationship with Russia.
The new law will also allow Russian to be the chosen language of people living in these regions and grant amnesty to separatists who had previously taken part in military action against Ukrainian forces.
President Petro Poroshenko has strongly defended the constitutional reforms giving a televised national address to the nation:
“Today, Ukraine confirmed its reputation as a reliable partner and strengthened the image of the country that fulfills Minsk agreements in contrast to Russia. If Moscow does not reconsider its position, individual sanctions against those involved in the annexation of Crimea and the occupation of areas in Donbass will be extended in the Autumn.”
The violence in central Kyiv left one person dead – a 25-year-old national guardsman who had only been called up in the spring, died from grenade splinters. At least another 125 people were injured.