A blast was also heard outside parliament, an AFP correspondent said, although the cause was not immediately known.
About a dozen people were reportedly injured, an AFP journalist said.
Several people were seen bleeding, including police officers and apparently journalists, and lying on the ground in front of the parliament, the journalist said.
The Western-backed constitutional reforms are required under the terms of a Western-backed peace deal signed in February, which called for Kiev to implement "decentralisation" by the end of this year.
A total of 265 lawmakers voted in favour of the reforms at a stormy session of parliament in Kiev, with protests both inside and outside the building.
Dozens of demonstrators scuffled with police, AFP journalists saw. Protesters fired at least one smoke grenade that sent up a cloud of black smoke outside the building.
Tear gas was used by both sides, an AFP correspondent said.
The controversial reforms have been sought by Kiev's Western allies, who see them as a way of trying to end armed conflict in the east that has claimed more than 6,800 lives over the past 16 months.
The reform bill grants more powers to regional and local lawmakers including in the eastern areas currently under rebel control.
But contrary to the expectations of separatists, it does not definitively hand the largely industrial eastern region the semi-autonomous status that the insurgents are seeking.
According to the text of the draft legislation, the region's status needs to be defined by a separate law.
Kiev and the West accuse Russia of backing the rebels militarily and in particular deploying its troops to the conflict zone, claims that President Vladimir Putin and the Kremlin have repeatedly denied.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
