The blast, outside the city's parliament buildings, knocked officers off their feet and witnesses reported seeing pools of blood on the ground near some of the wounded.

Dozens of police and members of the Ukrainian national guard have been injured in what started as a demonstration over a draft law to give special status to separatist regions.

Several people were seen bleeding and lying on the ground in front of the parliament building amid reports of 'several' explosions. One of the officers died from shrapnel wounds while ten more were left with serious injuries.

'He died on the operating table,' a spokeswoman for the National Guard, Svitlana Pavlovska, said.

Street battles broke out between dozens of demonstrators and police outside parliament as MPs backed on first reading controversial constitutional amendments giving more autonomy to pro-Russian separatists.

It was worst unrest in Kiev since a bloody popular uprising ousted Kremlin-backed Viktor Yanukovych early last year. 

Interior ministry advisor Anton Gerashchenko said the guardsman who died was a conscript.

Interior Minister Arsen Avakov initially said the officer, who is believed to be 24 or 25, died from a bullet wound to the heart but later wrote that he was apparently killed by a fragment of a grenade. 

'More than 30 people have already been detained. More to come,' Avakov said on Facebook, adding that people who threw 'several' explosive devices wore T-shirts with the logo of the Svoboda nationalist party.

Avakov said the protester who had thrown the grenade had been also detained.

He said the authorities had confiscated several grenades including an F-1 grenade which Avakov noted had a maximum radius to cause death and injury.

'Investigation and punishment will be unavoidable,' he said, calling the clashes an 'anti-Ukrainian war'.

Oksana Blyshchyk, a spokeswoman for Kiev police, said separately that around 100 police were injured including 10 in critical condition. 

(dailymail.co.uk)