A convoy of buses carrying Ukrainian Internal Troops soldiers left the Vasylkiv base on Tuesday morning and is now heading to the capital, Kyiv, in order to reinforce the Internal Troops' presence in the city and replace soldiers currently deployed there.

"The bus convoy is moving toward Kyiv. No clashes with protesters have been reported," a Kyiv region police spokesman told Interfax-Ukraine, denying earlier claims by political forces and the media that clashes had erupted between pro-European Union demonstrators and police.

A criminal investigation has been opened after protesters tried to stop police buses from leaving the Vasylkiv base, which is located outside Kyiv, he said.

All those who took part in these events will be identified and summoned for questioning, he added.

The 1+1 television station reported earlier that 15 or so buses carrying law enforcement personnel to Kyiv had broken through protesters' lines in the town of Vasylkiv on Tuesday morning.

A member of the UDAR opposition party's local branch, Serhiy Sabov, has confirmed that buses carrying Tyhr (Tiger) special operations units departed from Vasylkiv.