Censor.NET reports citing Interfax-Ukraine.
"The main version being worked out by the SBU, is a terrorist attack, and it is connected with his professional activities. He was the best counterintelligence agent in Ukraine," Hrytsak said after the farewell ceremony to Kharaberiush, who died in a car explosion.
"It is a matter of honor to find those who did it. We will do our best," the head of the SBU added.
After the farewell ceremony, Hrytsak handed the Order For Courage to the father of the deceased.
On March 31, a Toyota Land Cruiser SUV exploded in Mariupol market area, killing its driver, Ukraine's Security Service Colonel Oleksandr Kharaberiush. He died of extensive blood loss in the ambulance.
Kharaberiush was the deputy chief of the Donetsk SBU counter-intelligence unit.
Head of the Main Directorate of the National Police in the Donetsk region Viacheslav Abroskin said that one of the versions of the explosion is a terrorist attack organized by a 'DPR' raiding unit.