Both people are believed to be in critical condition.
The police have declared a major incident in the town of Amesbury in Wiltshire after two people were found unresponsive.
A statement from Wiltshire Police stated that it was originally believed that the people, a man and a woman, had been using crack cocaine or heroin, but that they are now being treated for exposure to an "unknown substance".
https://twitter.com/wiltshirepolice/status/1014304564919586822
The incident has occurred less than eight miles away from where Sergei Skripal and his daughter Yulia were apparently poisoned in Salisbury earlier this year. Salisbury is also in the county of Wiltshire.
Police have since said that they are keeping an "open mind" as to nature of the incident. The names of the people who have been hospitalised have not yet been made available to the public.
Areas that were frequented by the two people before they fell ill have been cordoned off by the police as a precautionary measure.
A Public Health England (PHE) spokesman said: "The current advice from PHE England, based upon the number of casualties affected, is that it is not believed that there is a significant health risk to the wider public. This will be continually assessed as further information becomes known."
