Dozens of radicals threw sound and smoke grenades as they surrounded Kiev’s presidential building. The radical Right Sector leader threatened Ukraine’s president with same fate as Yanukovich, criticizing the law giving special status to eastern regions.

Around 300 angry protesters wore masks and shouted nationalistic slogans as they tried to break through a police barrier. They carried red and black flags belonging to the radical Right Sector group.

The aggressive crowd was demanding that President Petro Poroshenko veto a bill that was passed by parliament earlier this Tuesday.

The new law gives special status to eastern regions of Lugansk and Donetsk, as well as amnesty to those who were fighting against government forces.

That particular status will also see early local election carried out this December and allow the use of the Russian language as an official one.

READ MORE: Special status to E. Ukraine regions, amnesty to combatants - parliament

In the meantime, the leader of the radical Right Sector Dmitry Yarosh described the law as "anti-national" on his Facebook page.

“Unless Poroshenko comes to senses, we’ll have a new president and commander-in-chief in Ukraine,” Yarosh warned. “If anyone doubts that it’s possible, he can write to Yanukovich. He can verify that impossible things can be made happen.”

Former President of Ukraine Viktor Yanukovich lost power in February as a result of mass protests in which the radical nationalist group played a key role.

It’s not the first time that Yarosh and his supporters have threatened the Ukrainian leader over his policies. In August, Right Sector demanded that the president sack some senior officers in the Interior Ministry, whom the radicals accused of persecuting their members.

The ultimatum was retracted a day later as the Right Sector said police had released its people previously arrested for alleged smuggling of arms from the combat zones in the east of the country.

Wednesday’s violent protest was not the first acts of violence in Kiev in the last couple of days. On Tuesday another radical rally devolved into violence when ultra-nationalists protested against several laws approved by the parliament, the Verkhovna Rada.

They burnt tires and even clashed with the National Guard right in front of the parliament building.

International law expert Alexander Mercouris believes that the radical element in Ukraine will continue the unrest over the president’s attempts to reach peace in the east.

“What we are seeing is an escalation within the Ukraine of the political crisis. For these people any kind of autonomy to the eastern regions utterly cuts against their ideology, which is of a centralized, ethnically united Ukrainian speaking Ukraine,” Mercouris told RT.