Police have cordoned off a street in Salisbury after a man fell ill in the city centre.
Wiltshire Police said they were dealing with an ongoing incident in Castle Street involving a man in his 30s.
The police cordon is near Zizzi restaurant where ex-Russian spy Sergei Skripal and his daughter Yulia dined before they fell ill.
The pair were discovered unconscious on a bench in March after being poisoned with the nerve agent Novichok.
On Twitter, Salisbury Police said: “There is nothing to suggest any wider risk to the public.
“Given the ongoing incident in Salisbury and Amesbury, we are taking highly precautionary measures to ensure public safety.
“We do not want people to be alarmed, but hope you understand the reasons behind this.”
A witness, who asked not to be named, said the man involved was a “local homeless guy” who was “sat on the floor, completely conscious, talking”.
He said he saw a paramedic putting on a chemical suit while another “was shouting at the man to stay put and stay on the floor”.
All the police officers had rubber gloves on, he added.