Oct. 23 (UPI) -- British authorities on Thursday arrested three men suspected of spying for Russia, according to London's Metropolitan Police.

Police in London arrested the three unidentified men -- 48, 45 and 44 -- under Britain's 2023 National Security Act on "suspicion of assisting a foreign intelligence service," authorities said.

"We're seeing an increasing number of who we would describe as 'proxies' being recruited by foreign intelligence services and these arrests are directly related to our ongoing to efforts to disrupt this type of activity," according to Commander Dominic Murphy, London's counter terror chief.

On Thursday, the three were arrested at west and central London addresses on suspicion of assisting a foreign intelligence service.

London's Metro Police added that searches were "ongoing at these addresses as well as another" residence in west London.