LONDON — Three men were arrested Thursday on suspicion of assisting Russia’s foreign intelligence service.

The Metropolitan Police arrested the men — aged 48, 45 and 44 — at addresses in west and central London. Searches are ongoing at those addresses as well as another west London address.

The capital’s police force said the alleged offenses related to Russia.

Counter Terrorism Policing London Commander Dominic Murphy 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.

“Anyone who might be contacted by and tempted into carrying out criminal activity on behalf of a foreign state here in the U.K. should think again.” 

Murphy added: “This kind of activity will be investigated and anyone found to be involved can expect to be prosecuted and there are potentially very serious consequences for those who are convicted.” 

Moscow was put on the enhanced tier of the U.K.’s Foreign Influence Registration Scheme in July, meaning anyone working for the Russian state needs to declare their activity or risk jail.

Three men were convicted earlier this year after an arson attack at a warehouse containing aid for Ukraine.