KIEV, April 03. /ITAR-TASS/. Head of Ukrainian Security Service Valentyn Nalyvaichenko confirmed that an assault force of security service’s commandoes Alfa was involved in suppression of a riot staged in the Ukrainian capital of Kiev on February 18. He made a statement at a media briefing on Thursday.

In his words, 108 Alfa commandoes were on the roof of Ukraine’s house of trade unions with firearms.

“There's no doubt shots were fired [in the direction of rioters],” Nalyvaichenko said.

The security service chief noted that Alfa commandoes left the house of trade unions over a fire breaking in the building on that day.

Security commandoes were also staying on the roof of other two buildings, one of which is situated on Kreshchatik Street and the another one on Kostelnaya Street in central Kiev, the country’s security chief said.

In his words, Alfa commandoes are undergoing investigative actions, they “agreed to co-operate with the investigation.”

Meanwhile, several security officers have fled the investigation by escaping to the Russian Republic of Crimea, he said.