Russian mercenaries with spy links increasing presence in Ukraine

Russian mercenaries with spies are expanding their presence in Ukraine in recent weeks.

Russian mercenaries with ties to Moscow's spies have increased their presence in Ukraine in recent weeks, stoking fears among some NATO members that Russia could try to engineer a pretext for an invasion, three senior Western security sources said.

They said their concerns had strengthened in recent weeks that a Russian incursion into Ukraine could be preceded by an information war, and cyber attacks on Ukraine's critical infrastructure such as electricity and gas networks.

Russia could also use the mercenaries to sow discord and paralyse Ukraine through targeted assassinations and the use of specialised weaponry, the sources said.

The United States warned again on Sunday that Russia could stage a "false flag" operation inside Ukraine to justify an invasion.

"It is likely that Russian mercenaries, under the direction of the Russian state, will be involved in any hostilities in Ukraine, potentially including a pretext for an invasion," said one Western security source, who spoke on condition of anonymity.

The Western security sources said mercenaries were deploying from Russian private military companies (PMCs) with close ties to the Federal Security Service (FSB), the main successor to the Soviet-era KGB, and the GRU military intelligence agency.

Among those deployed in recent weeks was a former GRU officer who also worked in the Wagner mercenary group. The former officer has gone to Donetsk, one of two regions in eastern Ukraine controlled by pro-Russian separatists since 2014, the sources said.