KIEV, Aug. 31 - A member of Ukraine's National Guard was killed and scores of people were injured Monday in clashes between police and nationalist protesters in Kiev as lawmakers gave initial backing to a contested bill boosting autonomy in the country's breakaway regions, AFP reported.

Major powers voiced deep concern at the bloodshed, which the Ukrainian government blamed on ultra-nationalists.

It was the worst unrest in the capital since a popular uprising ousted Moscow-backed president Viktor Yanukovych early last year.

Prime Minister Arseniy Yatseniuk pointed the finger at ultra-nationalists for the violence, which left 125 injured, six seriously, according to the interior ministry.

"At a time when Russia and its bandits are seeking to destroy the country but are unable to do this on the front line, the so-called pro-Ukrainian political forces are trying to open a second front inside the country," Yatseniuk said in a nationwide address.

President Petro Poroshenko branded the violence a "stab in the back" and said the perpetrators deserved "severe" punishment.

The European Union, Russia, the United States, France and Germany expressed their disquiet.

"Today's events are very worrying," said EU foreign affairs head Federica Mogherini while Russian President Vladimir Putin's spokesman condemned the "displays of violence" in Kiev.

In Washington, deputy US State Department spokesman Mark Toner said "in a democratic society, grievances must be addressed peacefully and lawfully".

"We also call for a full investigation into the cause of today's violence. Those responsible should be held accountable," Toner said.

The violence flared shortly after MPs backed the first reading of constitutional reforms that critics have branded "un-Ukrainian" for giving the Moscow-backed insurgents greater powers in the east.

A total of 265 lawmakers voted in favor of the legislation.

The stormy session saw some MPs angrily try to disrupt the vote, which they condemned as "pro-Vladimir Putin". Some shouted "Shame!"

The reforms were agreed as part of a February peace deal brokered by Germany and France that called for Kiev to implement decentralization by year's end.

Outside parliament, baton-wielding riot police clashed with the protesters.

A loud blast was heard and clouds of black smoke billowed into the air as demonstrators threw what security forces said were grenades.

Some of the injured lay bleeding on the ground in front of the parliament building, with many suffering injuries to their arms and legs. Most of those hurt were in uniform.

The authorities said a member of the National Guard, believed to be a 24-year-old conscript, died of his injuries.

Interior Minister Arsen Avakov initially said he died from a bullet wound to the heart but later revised his remarks, saying he was killed by shrapnel from a grenade.

Avakov said a deputy interior minister was also hurt.
Several journalists were also injured.

The interior ministry blamed the nationalist Svoboda party for the unrest, saying those detained included a member of the party's paramilitary unit, who was accused of throwing the grenade.

"More than 30 people have already been detained. More to come," Avakov said, adding that people who threw "several" explosive devices were wearing T-shirts with the Svoboda logo. (afp/ez)