The Czechs, earlier this week, expelled 18 Russian diplomats suspected of being intelligence operatives involved in the explosion at a Czech arms depot in 2014 which killed two people.
Two Russians suspected of carrying out a nerve agent attack in the UK in 2018 are now also being linked to the blast.
Tensions with Russia over the health of opposition leader Alexei Navalny and the military build-up of Russian forces at the Ukrainian border were discussed by EU foreign ministers on Monday.
On Wednesday, several European Parliament Group leaders issued a strongly-worded statement voicing concern at recent events.
It reads, “We are shocked by the recent reports of the involvement of Russian GRU intelligence services in the 2014 explosion of an arms depot in the Czech Republic, in which two Czech citizens were killed.
“The same agents are linked to the poisoning of Sergei and Yulia Skripal in the United Kingdom in 2018.”
“We are shocked by the recent reports of the involvement of Russian GRU intelligence services in the 2014 explosion of an arms depot in the Czech Republic, in which two Czech citizens were killed"
“This is another attack by people affiliated to the Russian state on a sovereign territory in the European Union. It demonstrates the disturbing lengths that Russia will go to to undermine Europe, and reconfirms the dangerous malign behaviour of the Russian government.”
It adds, “An attack with the involvement of Russian GRU intelligence services on European citizens in any of the EU Member States should be viewed as a serious attack on the entire EU. This is an unacceptable act of hostility.”
“Today we stand in full solidarity with the Czech Republic and we call on the Member States and the Council to also show their solidarity by adopting a strong, common and concrete action towards Russia in response to this attack.”
It is signed by Manfred Weber, Iratxe García-Perez, Dacian Cioloș, Philippe Lamberts and Ska Keller and Ryszard Legutko and Raffaele Fitto
They are leaders of the EPP, S&D, RE, Greens/EFA and ECR groups in the European Parliament
“An attack with the involvement of Russian GRU intelligence services on European citizens in any of the EU Member States should be viewed as a serious attack on the entire EU. This is an unacceptable act of hostility”
The explosion on 16 October 2014 tore apart an ammunition storage depot in a forest at Vrbetice in the Czech Republic. Detective work by the Czech authorities has pointed the finger at Moscow – specifically Russia's GRU intelligence agency.
Czech police have identified two men in connection with the blast - Alexander Mishkin and Anatoly Chepiga - who are also accused of involvement in an attack using the nerve agent Novichok in the English city of Salisbury three years ago.
Russia has since announced that 20 diplomats from the Czech Republic will be expelled in retaliation.