A man and woman are in a critical condition after being exposed to an "unknown substance", prompting British police to declare a "major incident" as they were found unconscious close to where a former Russian spy and his daughter were poisoned with a deadly nerve agent.
The pair, in their 40s, were found unconscious in a property on Saturday in what was thought to be in a drugs-related incident in Amesbury, Wiltshire, the BBC reported today.
Further tests on the substance are being carried out to identify it, the report said.
Amesbury is about 16 kilometres from Salisbury, where former Russian spy Sergei Skripal and his daughter were poisoned.
Skripal and daughter Yulia were poisoned with Novichok, a suspected military nerve agent, in March.
Police said they are "open-minded" about the cause after a couple were found at a house in Muggleton Road, Amesbury.
While it was not clear whether a crime had been committed, the force said, a number of places in Amesbury and Salisbury known to have been frequented by the couple had been cordoned off.
"It was initially believed that the two patients fell ill after using possibly heroin or crack cocaine from a contaminated batch of drugs," Wiltshire Police said.
"They are both currently receiving treatment for suspected exposure to an unknown substance at Salisbury District Hospital," it added.
The couple are believe to have attended a family fun day at Amesbury Baptist Church on Saturday afternoon before they were found unconscious in the property.
Roy Collins, church secretary, said "nobody else has suffered any ill-effects" from attending the community event and "there was nothing going on that was nefarious".
"There have been no reports of any other incidents," he said.
"We are all quite puzzled and shocked - naturally the connection with Salisbury and recent events there mean there is a heightened public interest."
Local resident Jake Murphy said he was watching the football on Tuesday night when "all these police cars appeared".
"I didn't know what was happening," he said.
A government spokesman said ministers were "being kept up to date about the incident in Amesbury".
Wiltshire's Police and Crime Commissioner Angus Macpherson said the police had worked hard at "containing any risk that might be there".
"There's no reason to think it's connected with matters of last month," he said.
"I haven't seen anything in this incident yet that I would consider to be an overreaction in terms of previous incidents, it all seems fairly textbook."
Public Health England said it did not believe there was a "significant health risk" to the wider public, although its advice was being continually assessed.
The hospital where the pair has been admitted was "open as usual" and advised patients to attend routine appointments unless contacted and advised to do otherwise.
The March incident in Salisbury sparked a diplomatic row between the UK and Russia after British investigators blamed Moscow for the nerve agent attack.
Russia has denied the allegations, but more than 20 other countries kicked Russian diplomats out of their countries in a show of support for the UK.
Both Skripal and his daughter Yulia have since been discharged from hospital.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)