Sept. 6 (UPI) -- A day after two Russians were charged in the case, the Kremlin on Thursday denied having anything to do with the poisoning of former Russian spy Sergei Skripal.
British prosecutors charged the pair with attempted murder and use of novichok, a banned Soviet-era nerve agent.
Officials said the suspects, Alexander Petrov and Ruslan Boshirov, fled Britain and returned to Russia, but could be arrested if they enter any European Union country. Russia will not extradite its own nationals.
The United States, France, Germany and Canada sided with their British allies, saying the Russian government "almost certainly" approved Skripal's poisoning.
British Prime Minister Theresa May said it was "not a rogue operation" and "almost certainly" approved by senior Russian leadership.
The countries released a joint statement that said, "We the leaders of France, Germany, the United States, Canada and the United Kingdom, reiterate our outrage at the use of a chemical nerve agent, known as novichok, in Salisbury on March 4."
Novichok is banned by the Chemical Weapons Act.
The statement went on to say they believe Petrov and Boshirov are Russian intelligence officers working for the GRU.
Russian authorities countered by calling the accusations "disgusting anti-Russian hysteria."
"We again say that neither the upper leadership, nor the leadership a rank lower or any official representatives had or have anything to do with the events in Salisbury," Kremlin spokesman Dmitry Peskov said in a conference call. "Any suggestions of this kind or accusations, I repeat, are unacceptable."