The chief of the Security Service of Ukraine (SBU) Vasyl Hrytsak has said that the main version of the death of a member of the Security Service, Colonel Oleksandr Kharaberiush in Mariupol, Donetsk region is a terrorist act related to the professional activities of the deceased.

"The main version, which is being developed by the SBU, is a terrorist act, and this is connected with his professional activities. We clearly understand that they came for him. He was the best counterintelligence officer in Ukraine," Hrytsak told journalists in Mariupol on Sunday after the farewell ceremony with Kharaberiush, who died as a result of a car explosion on Friday.

According to the SBU chief, when the incident was reported to President Petro Poroshenko, he made an unequivocal decision to reward the deceased with a military medal "For Courage." "For us it is a matter of honor to find those who did it [undermined the car]. We will do our best," Hrytsak said.

After the farewell ceremony the SBU chief handed the medal over to the deceased's father, a correspondent of the Kyiv-based news agency Interfax-Ukraine reports.

As reported, the explosion occurred at the junction of Metalurhiv Avenue and Kafaiska Street in the central district of Mariupol at 8:35 a.m., the Donetsk regional police's liaison department said. Kharaberiush himself, who served as deputy head of the main counterintelligence department of the Donetsk SBU Directorate, died on the spot.

Viacheslav Abroskin, chief of the National Police department in the Donetsk region, said on Facebook a terror attack perpetrated by a sabotage-and-reconnaissance group from the self-proclaimed Donetsk People's Republic (DPR) was being pursued among the possible theories of the explosion. Police patrols are being reinforced in Mariupol and across the Donetsk region, he said.