A British couple who both fell ill on Saturday after visiting Salisbury, the English town where a former Russian double agent and his daughter were poisoned in March, were exposed to Novichok, the same military-grade nerve agent used in that attack, Britain’s top counterterrorism official said on Wednesday. Metropolitan Police Assistant Commissioner Neil Basu told reporters that tests carried out by chemical weapons experts at Porton Down, the British military lab near Salisbury, “confirm that the man and woman have been exposed to the nerve agent Novichok, which has been identified as the same nerve agent that contaminated both Yulia and Sergei Skripal.”

#BREAKING British police confirm two people have been poisoned by novichok - the same nerve agent used on former Russian agent Sergei Skripal and his daughter Yulia pic.twitter.com/HeMbV2HPgf — News Breakfast (@BreakfastNews) July 4, 2018

The couple, identified by the British media as Dawn Sturgess and Charlie Rowley, were hospitalized on Saturday and are currently in critical condition in Salisbury District Hospital, where the Skripals were treated after an apparent assassination attempt in March. Although Basu said the poison was Novichok, one of a series of chemical weapons developed by Russia, “we are not in a position to say whether the nerve agent was from the same batch that the Skripals were exposed to.” Speaking to Parliament on Thursday, Britain’s home secretary, Sajid Javid, connected the new episode to what he called the “reckless” decision “taken by the Russian government” to deploy a chemical weapon in Salisbury in March. “It is now time,” Javid added, “that the Russian state comes forward and explains exactly what has gone on.”

"The eyes of the world are currently on Russia" - @sajidjavid has called for the #Russian state to come forward and explain this latest #novichok poisoning.



Here's everything you need to know: https://t.co/Rwvl7lRrfu pic.twitter.com/mwwrqZpg7W — Sky News (@SkyNews) July 5, 2018

Russia’s foreign ministry spokesperson, Maria Zakharova, responded by accusing British Prime Minister Theresa May of “intrigue and games with chemically poisonous substances.”

The Russian foreign ministry's response to latest Novichok poisoning: "We call on Theresa May to stop the intrigue and games with chemically poisonous substances and to stop obstructing a joint investigation of what happened in Britain with Russian citizens." pic.twitter.com/44aTkVkIpD — Alec Luhn (@ASLuhn) July 5, 2018

Since the poisoning of the Skripals, Russian officials have promoted a variety of conspiracy theories suggesting that the attack was staged by British intelligence to discredit the Kremlin. The new victims live in the town of Amesbury, but reportedly visited Queen Elizabeth Gardens in Salisbury last week. That park, which is only eight miles from the couple’s home, is one of five sites now cordoned off by the police.

Lush House car park and Harcourt surgery in Salisbury have been re-opened to public. Police officers have readjusted cordon to perimeter of Queen Elizabeth Gardens. pic.twitter.com/xPSoAQuwId — Caroline Bannock (@carlanine) July 4, 2018

Investigators are currently trying to determine if Sturgess and Rowley might have accidentally come into contact with residue of the nerve agent left behind by the Skripal attackers, Ben Wallace, Britain’s minister of state for security, told Deborah Haynes, the Times of London defense editor.

BREAK - @BWallaceMP says "working assumption" is that #Amesbury couple are victims of the #novichok nerve agent used in original attack (blamed on Russia) against the #Skripals and not specifically targeted in any new attack — Deborah Haynes (@haynesdeborah) July 5, 2018

Russian diplomats entered the social media discussion of the incident by mocking the idea that the Russia was to blame for the attempted assassination of the Skripals and promoting a conspiracy theory based on the proximity of the poisonings to Britain’s own chemical weapons lab at Porton Down.

How dumb they think ?? is to use “again” so-called “Novichok” in the middle of the FIFA World Cup and after the special session of the CSP (convened by the way by ??) that gave the #OPCW attribution functions. The show must go on? pic.twitter.com/a9FdJceWIv — Russian Embassy in NL???? (@rusembassynl) July 5, 2018

Two British subjects were allegedly poisoned in #Amesbury by "Novichok". Fact: Porton Down military biotech lab capable of producing said nerve agent is in close proximity to both #Salisbury & #Amesbury. Question: What pretext will be invented to lay blame on Russia this time? pic.twitter.com/Ld9eiRsZxX — Russia in RSA ?? (@EmbassyofRussia) July 5, 2018

Dan Kaszeta, a chemical weapons expert based in London, noted that the class of Russian nerve agents known as Novichoks were designed during the Cold War to outlast defensive measures taken by enemy soldiers.

So far, this is a logical hypothesis. After all, nerve agents are indiscriminate weapons and the Novichoks were engineered with persistent contamination of land and equipment in mind. https://t.co/0oTUd4JY0j — Dan Kaszeta (@DanKaszeta) July 4, 2018

Mark Urban, the diplomatic editor of the BBC program “Newsnight,” reported on Wednesday that Britain told NATO allies in March that it had intelligence showing that Russia had been keeping the Skripal family under surveillance and that Russian military intelligence had hacked into Yulia Skripal’s email accounts.

The poisoning of two British citizens by a Russian-developed nerve agent, even if accidental, comes at an awkward moment, as Russia tries to rehabilitate its international image. The news broke as Russia was earning plaudits for hosting a successful World Cup tournament, in which its national team has so exceeded expectations that it could even reach the semifinals next week, where one of two possible opponents is England.

Good luck to @England today! Who do you think will win the Russia-England semifinal? #scherzo — Russian Embassy, UK (@RussianEmbassy) July 3, 2018