The Netherlands will expel two alleged Russian spies that were working as accredited diplomats, the Dutch intelligence service announced on Thursday.

The Netherlands' General Intelligence and Security Service (AIVD) said the two diplomats were working for Russia's civilian SVR intelligence service. They were allegedly gathering intelligence on high-tech companies in the Netherlands.

AIVD said one of the Russians had "built a substantial network of sources, all of which are or have been active in the Dutch high-tech sector." The officer allegedly targeted firms dealing with artificial intelligence, semiconductors and nanotechnology, for uses in both civil and military applications, including in weapons systems.

"Some individuals were paid by the intelligence officer in exchange for information," it said.

The second officer allegedly had a "supporting role."

"Both intelligence officers have been declared 'persona non grata' by the Ministry of Foreign Affairs. This means that they are no longer allowed to operate as diplomats in the Netherlands and must soon leave our country," it said.

Follows EMA hack

It comes after the Netherlands-based European Medicines Agency was targeted in a cyberattack that also gained access to some coronavirus vaccine data. However, there is no evidence of a link between the two events.

Also on Wednesday, Danish prosecutors charged a Russian citizen with espionage for allegedly providing information about Danish energy technology to an unnamed Russian intelligence service.

Russia has yet to respond to the expulsions. However, the move will probably place further strain on the already tense relations between the two countries, which soured following the 2014 downing of Malaysia Airlines Flight 17 over Ukraine.

The Netherlands expelled four purported Russian spies in 2018 after they were found allegedly trying to hack the Organisation for the Prohibition of Chemical Weapons in The Hague, from a car parked in a neighboring hotel.