Two people were left in a coma in the same vicinity as a former Russian spy who was exposed to the same nerve agent, officials said.

British police say two Britons who fell critically ill in the town of Amesbury were exposed to nerve agent Novichok, the same material used to poison a former Russian spy in a nearby area last spring.

Medical officials said Wednesday people who had been in the area where the couple had been should take precautions and wash their clothes.

Police said it is unclear if this incident is linked to the earlier poisoning of Sergei and Yulia Skripal, or if the batch was the same as the one that poisoned them on March 4.

Counter-terrorism police detective Neil Basu said it is unclear if the couple were targeted or if the poisoning was accidental.

The man and woman were hospitalized Saturday at Salisbury District Hospital, where authorities initially believed they might have taken a contaminated batch of heroin or crack cocaine.

"However, further testing is now ongoing to establish the substance which led to these patients becoming ill and we are keeping an open mind as to the circumstances surrounding this incident," police said. "At this stage, it is not yet clear if a crime has been committed."

The Associated Press contributed to this report