Ukrainian authorities have opened investigations against four top officials in Kiev and suspended two of them from office over the violent police response to a small demonstration last month.

Prosecutor-general Viktor Pshonka said the deputy head of the national security council, the head of the Kiev city administration, as well as the then-head of Kiev police and his deputy are being investigated on suspicion of abuse of office in the crackdown on protesters.

Prosecutors will seek to place the suspects under house arrest.

Dozens of protesters, many of them students, were injured after riot police violently dispersed a small rally on Kiev's Independence Square in the early hours of November 30, beating protesters on the heads and limbs, dragging them on the ground, and chasing fleeing activists.

Shortly after Mr Pshonka's announcement, President Viktor Yanukovych suspended two of the senior officials under investigation, Kiev city head Oleksandr Popov and deputy head of the national security council Volodymyr Syvkovych, while investigations continue.

He stopped short, however, of fulfilling the protesters' demand that the president fire two of his close allies - prime minister Mykola Azarov and beleaguered interior minister Vitali Zakharchenko, whom the protesters view as responsible for the crackdown.