British police have confirmed that two people critically ill in hospital in southern England were exposed to the nerve agent Novichok.
That's the same substance used to poison former Russian spy Sergei Skripal and his daughter Yulia in March.
A major incident was declared in the town of Amesbury, where the man and woman were found unconscious on Saturday.
Al Jazeera's Sonia Gallego reports from Salisbury.
