Police in the UK have confirmed the substance which left two people critically ill in Wilsthire is the same nerve agent used to poison ex-Russian spy Sergei Skripal and his daughter.
The pair are both British nationals - and were found unconscious in Amesbury, which is just a few miles from where the Salisbury attack happened.
The Metropolitan Police say there was "nothing in their background" to suggest they were targeted.
The victims have been named locally as Charlie Rowley (45) and Dawn Sturgess (44).
— Metropolitan Police (@metpoliceuk) July 4, 2018
Sam Hobson, a friend of the pair, said: "I came around Charlie's house in the morning and there was loads of ambulances outside and his girlfriend was getting taken away and he said she was complaining of a headache in the morning.
"She went into the bathroom to have a bath and he heard a thump and she was in there having a fit, foam coming out of her mouth."
He added: "He [Mr Rowley] was sweating loads dribbling and you couldn't speak to him. He was making funny noises and he was rocking backwards and forwards. There was no response for me, he didn't even know I was there, he was in another world - he was hallucinating."
Metropolitan Police Assistant Commissioner Neil Basu has been updating reporters.
"The Counter Terrorism Policing Network is now leading the investigation into this incident.
"This evening I have received test results from Porton Down which show that the two people have been exposed to the nerve agent, Novichok".