A series of security leaders in Ukraine have been dismissed.

The decree dismissing three leaders of the Ukrainian Internal Security Service (SBU) was posted on the website of President Volodymyr Zelensky's office on August 15.

Accordingly, the head of the Kyiv Oblast SBU, Serhiy Zayats, and his counterpart in Ternopil Oblast, Yuriy Boreichuk, were dismissed. The head of the Lviv Oblast SBU, Artem Bondarenko, was relieved of his duties and took over leadership of the Kyiv Oblast security agency.

President Zelensky at a meeting in Kyiv, Ukraine, on August 12. Photo: Reuters.

The orders did not specify the reasons for the dismissal of the SBU leaders.

President Zelensky last month suspended the jobs of SBU Director Ivan Bakanov, his childhood friend, and Prosecutor General Iryna Venediktova on charges of "failing to prevent Russian espionage."

In late March, the Ukrainian president also dismissed Naumov Olehovych, head of the Internal Security Service of the SBU, and Kryvoruchko Oleksandrovych, former head of the Kherson Oblast Security Service, for "treason and violation of oath of allegiance."

In July, Zelensky said that hundreds of investigations into acts of treason had been launched. The threat from spy networks within the government, the church, intelligence agencies, and pro-Russian citizens in the east has caused Ukraine considerable difficulties in recent years. The problem has become even more prominent in the current conflict.

The Ukrainian president paid particular attention to the SBU, a force of 27,000 members and considered the largest in Europe. Western allies argue that the agency operates in too many areas, is prone to corruption, and fails to fulfill its role in hunting down spies.