Authorities said the two, who were found unconscious over the weekend, are in critical condition in the same Salisbury hospital where the former Russian spy and double agent Sergei Skripal and his adult daughter, Yulia, were treated after being poisoned by the Soviet-era nerve agent known as Novichok four months ago.

"It's not looking like a new attack", said Hamish De Bretton-Gordon, a former commanding officer of the British Army's chemical and biological weapons unit.

Health officials have urged local people who recently visited any of five sites cordoned off by police in Salisbury and Amesbury since on Tuesday to take precautions, including washing clothing and cleaning other items that could be contaminated.

Police have been unable to locate the source of the contamination and have warned that they can not rule out more people falling ill.

British police have confirmed that a man and woman critically ill from nerve-agent poisoning were exposed to the toxin by handling a contaminated item.

Late on July 4, Britain's top counterterrorism officer, Neil Basu, said tests had found that the two Amesbury residents had been exposed to Novichok, the same nerve agent that sickened the Skripals.

Police said there was no evidence the latest victims had visited any of the sites linked to the Skripals, which have since been decontaminated.

The Counter Terrorism Policing Network is leading the investigation in Amesbury, which is eight miles from the Salisbury poisoning site.

If remnants of the March attack are proven, it could raise wider concerns that health officials failed to eliminate exposure risks after an extensive cleanup.

Statue of Liberty climber awaits court appearance in NY
Liberty Island has been evacuated while they attempt to get her down, according to Jerry Willis with the National Park Service . After a three hour standoff, police officers cornered the woman and helped her down, then took her into custody.

Police said, "We are not in a position to say whether the nerve agent was from the same batch that the Skripals were exposed to".

The huge inquiry has yet to lead to the public identification of any suspects after a lack of CCTV in Salisbury apparently hampered efforts to track any would-be assassins.

The officer added that after tests at the Porton Down facility, which assisted in diagnosing the poisoning in Salisbury, scientists recognized the use of "the same nerve agent that contaminated both Yulia and Sergei Skripal".

Alastair Hay, Professor Emeritus of Environmental Toxicology at the University of Leeds, said there is "no specific method for the detection of Novichok in the environment" because the use of the nerve agent was not considered likely when monitors were designed.

British officials blamed the Skripals' poisoning on Russian Federation.

"It is completely unacceptable for our people to be either deliberate or accidental targets, or for our streets, our parks and towns to be dumping grounds for poison", he told parliament.

Novichok remains highly toxic for a considerable period of time, so even the tiniest trace remaining in a container picked up by the victims could account for their severe illness.

"They can come and tell us what happened".

Confirming Britain will be consulting with worldwide partners and allies following the latest developments, Mr Javid said: "The eyes of the world are on Russian Federation, not least because of the World Cup".