British police have declared a "major incident" after two people were exposed to an unknown substance in a town near where a former Russian spy and his daughter were poisoned with nerve agent.
In a statement, Wiltshire Police said a man and a woman - both in their 40s - are in critical condition after being found in Amesbury, eight miles (13 kilometres) from Salisbury, where Sergei and Yulia Skripal were poisoned on March 4.
Police cordoned off places the two people visited before falling ill, but public health officials say there is not believed to be a wider risk. A police cordon could be seen in place at the Amesbury Baptist Church on Wednesday morning, believed to be one the last places the couple was seen. They were hospitalised on Saturday and authorities at first thought they might have taken a contaminated batch of heroin or crack cocaine.
Britain accuses Russia of poisoning the Skripals with a Novichok nerve agent. Moscow denies the allegation. The poisoning sparked a Cold War-style diplomatic crisis between Russia and the West, including the expulsion of hundreds of diplomats from both sides.