Ukraine’s domestic security service has arrested two people allegedly working for Russian intelligence services who planned to kill Ukraine’s defence minister and the head of its military intelligence agency, The Guardian transmits.

The security service of Ukraine foiled the alleged plot by the Russian GRU military intelligence agency to use a sabotage group to carry out three murders including that of a prominent Ukrainian activist, the agency said in a statement on Monday.

The suspects, one a resident of the eastern Luhansk region held by Russia-backed separatists and the other a resident of Ukraine’s capital, Kyiv, were promised up to $150,000 (£124,000) by Russian handlers for the murder of each of their targets, the SBU said.

The man from Luhansk region entered Ukraine from Belarus and was detained in the city of Kovel in north-western Ukraine along with the Kyiv resident, the statement said.

Russia invaded Ukraine on 24 February and security for top officials is extremely tight. Kyiv’s government district is cordoned off with checkpoints manned by armed men. Sandbags are piled up in the windows and entrances of government buildings.

The SBU has been in the spotlight in recent weeks after President Volodymyr Zelenskiy forced out its head and the state prosecutor general last month, citing dozens of cases of collaboration with Russia by officials in their agencies.