[Salisbury Journal] A cordon is in place on the high street, also affecting New Street, Crane Street and the entrance to the Cathedral Close.It is believed at least one person has "fallen ill" at the scene, with witnesses describing police "covering someone up" with a blanket.
People inside the Old Ale House pub have been told they cannot leave, and crews are putting on hazmat suits outside.
Emergency crews in white suits and face masks are inside Prezzo, and other officers in full hazmat suits are standing by.
A fire engine, ambulance, four police cars and an incident response unit are at the scene.
Police were called by the ambulance service to Prezzo at 6.45pm following a medical incident involving a man and a woman.
The restaurant and surrounding roads have been cordoned off "as a precautionary measure" while officers attend the scene and establish the circumstances surrounding what has led them to fall ill.
Another witness, Sam Proudfoot said there was "a man in a full white body suit with a mouth mask" at the scene.
It comes after Wiltshire Police issued a warning to drug users in the county as they believed the toxic opioid fentanyl is currently in circulation.
There is currently no confirmation on whether the incident is linked to ongoing nerve agent investigations.
More as we have it.