About 100 other officers were injured in the clashes, ten of them seriously. Some of the officers were injured in the blast. One of them died from shrapnel wounds, interior minister Arsen Avakov said.
No injuries were immediately reported among the approximately 100 protesters, most of whom were members of Svoboda, a nationalist party that holds only a handful of seats in parliament. The protesters were carrying sticks and truncheons. Some of them were masked.
Kiev mayor Vitali Klitschko described the clashes as “a bloody provocation” and called for the prosecution of the attackers. Mr Avakov said that about 30 people have been detained, including the person who threw the grenade.
The decentralisation of power was a condition of a truce signed in Minsk in February aimed at ending the fighting between Ukrainian government troops and Russia-backed separatists that has left more than 6,800 dead since April 2014.
But some Ukrainians oppose changing the constitution, saying it would threaten the country’s sovereignty.
A total of 265 deputies in the 450-seat parliament gave preliminary approval yesterday to the changes proposed by president Petro Poroshenko. Three parties, however, opposed the constitutional changes.
“This is not a road to peace and not a road to decentralisation,” said the leader of one of those parties, former prime minister Yulia Tymoshenko. “This is the diametrically opposite process, which will lead to the loss of new territories.” Parliamentary speaker Vladimir Groisman denied changes would lead to the loss of the Donetsk region, where there have been clashes with separatists.
“There is no hint of federalism. Ukraine was, is and will be a unified state,” Mr Groisman said.
With the decentralisation bill, Mr Poroshenko, who was due to address the nation last night, found himself in a tight spot. While Ukrainian nationalists fear the bill would incite separatism, Russia-backed rebels and Moscow say the bill doesn’t give regions enough power.
A final vote on the constitutional changes will be held during parliament’s autumn session, which begins today. Mr Avakov blamed the clashes on the Svoboda party, which polled under 5 per cent in last year’s parliamentary election, and its leader, Oleg Tyahnybok, who stood side by side with him during the 2013 anti-government protests which toppled then-president Viktor Yanukovich in February 2014.
“No political differences can justify what you did outside the Rada today,” Mr Avakov said, referring to the parliament.
Svoboda blamed the government, saying that it “provoked Ukrainians to protest” by presenting a bill which is tantamount to “capitulation to the Kremlin.”