British Prime Minister Theresa May says it's "highly likely" Russia was responsible for the poisoning of ex-spy Sergei Skripal.
May says the Russian ex-spy poisoned in England was exposed to a military-grade nerve agent of a type produced by Russia.
May says Russia's ambassador to the UK has been summoned to explain how a Russian nerve agent turned up in Salisbury, the English city where Skripal, 66, and his daughter Yulia, 33, were poisoned. They remain in a critical condition in hospital.
The pair were discovered in a comatose state on a bench near a shopping centre in the quiet English city last week. British authorities said the two had been targeted with a rare nerve agent. A total of 21 people have received medical treatment after the mysterious attack.
The Prime Minister says if Moscow is proven to be behind the poisoning, her government will consider it an "unlawful use of force" by Russia. She labelled the attack a "reckless and despicable act".