On this occasion, the cause was said to be a so-far unexplained fire that had broken out in a gunpowder processing unit.
Italian and Bulgarian officials both sought to play down any Russian involvement in the incidents.
But like with the cases in Estonia, Italy and Bulgaria, Russia very rarely leaves any evidence that would allow the attacks to be directly attributed to Moscow.
A Western intelligence assessment, previously reported by The Telegraph, explained how Russia’s GRU military intelligence agency, known for its attacks on foreign soil using highly trained agents, had since turned to using criminal gangs.
In an interview with The Telegraph last March, Normunds Mežviets, the head of Latvia’s state security service, said: “In our experience, we don’t see officers of the GRU travelling here physically to our country.
“No, they stay in Russia where it’s safe. They’re not taking any risks for their own operational and physical security.”
Instead, GRU officers cultivate sources within criminal gangs to act as intermediaries in the targeted country using online messaging apps such as Telegram.
These middlemen then dish out tasks to local recruits, who are paid in cryptocurrency and often never know they are working for Russia.
Kremlin seeking to sow discord within Nato
The covert nature of the Kremlin-ordered attacks is seen as a deliberate ploy to sow discord among Nato allies.
Eastern member states, such as Poland or the Baltics, have been vocal in calling out Russia’s aggression in Europe.
While the Latvians did not explicitly blame Russia, they did confirm the three suspects had been detained under powers used to tackle criminals “providing assistance to a foreign state in action directed against another state”.
But those countries further west, such as Italy and Germany, are often unwilling blame Moscow over fears of an escalation.
It is this division between Western allies that the Kremlin is seeking to expose.