"The Russian Ambassador will be summoned to the Swedish foreign ministry tomorrow in connection with Russia's accusations that Sweden could be the source of the poison that was used during the attempted murder in Salisbury," the Swedish foreign ministry said.
Earlier, Russian Foreign Ministry spokeswoman Maria Zakharova said that the most likely sources of origin of the А-234 substance were the United Kingdom, Slovakia, the Czech Republic, Sweden and, possibly, the United States.
Following the incident, UK Prime Minister Theresa May said that it was "highly likely" that Russia was responsible for the incident.
On Wednesday, Theresa May announced a package of anti-Russian measures, which included the expulsion of Russian diplomats from the UK, and the suspension of bilateral contacts between countries.
Russian authorities categorically refute its connection in the poisoning of the Skripals.