Participants in a rally entitled "March for Impeachment," during the storming of the Zhovtnevy Palace (October Palace) on Sunday, December 17, used gas of unknown origin with a strong impact that had not been used before and the police are identifying those who sprayed it, as well as people who stormed the building, Deputy Head of the National Police of Ukraine and Head of the Main Office of the National Police in Kyiv Andriy Kryschenko has said.

He told Interfax-Ukraine on Monday that initially the rally of former Georgian president and leader of the Movement of New Forces party Mikheil Saakashvili passed calmly.

"We used police officers based on the experience of past rallies. There was the same number of people as in previous times. We counted 2,500-3,000 of them. About half of them were brought, and others were those walking on Khreschatyk," he said.

He said that the situation was calm until calls were made to go to the Zhovtnevy Palace.

"At one point, Saakashvili called on everyone to come to the Zhovtnevy Palace. These slogans were heard from the stage, and nothing was announced from the stage that someone was waiting for them there and that someone would lease anything to them. Of course, police security was tightened, because it is an administrative building, and we knew that a number of children's performances and other events were planned there. A jazz concert took place on that day, and there were many women, children, a thousand civilians who listened to the classics of world jazz," Kryschenko said.

Speaking about the attempt of protesters to seize the building of the Zhovtnevy Palace, he said: "The protesters attempted to enter the building, tear gas was used, and it was unusual one."

In this context, Kryschenko said: "We will now identify the people who used this gas. It is not simple gas from spray cans. There are a lot of people poisoned, our employees, servicemen of the National Guard. The primary reaction to gas was very strong."