Former Ukraine President Viktor Yanukovych "directly led" protester killings during demonstrations in Kiev that led to his ouster, the country's security service chief said Thursday.
Ukraine's new government also detained 12 members of the country's disbanded "Berkut" riot police Thursday on suspicion "mass murder," relating to the fatal shootings.
More than 100 people died in the uprising that led to Yanukovych's ouster. Most are thought to have been killed at the hands of police snipers.
"The planned anti-terrorist operation, and in fact the organization of mass killings of people, was directly led by former President Yanukovych," Special Forces chief Valentyn Nalyvaichenko told a press conference reported by the Interfax Ukraine news agency.

Meanwhile, general prosecutor spokesman Vasyl Zoria told Reuters: "By this morning 12 people had been detained, all of them suspected of mass murder on Institutska Street." His comments were also reported by Interfax Ukraine.
Berkut translates to "golden eagle" and signifies a predator capable of swooping quickly onto its prey. Zoria told Interfax that the group of 12 includes the commander of the so-called "Black Company" special unit.
Institutska was one of the roads leading off Independence Square - also known as the Maidan - which was the heart of the protest movement. Since the end of the protests in February, the street has been informally renamed the "Avenue of Heaven's Hundred," a reference the people shot dead there.
Reuters contributed to this report.