Two more people in the U.K. have been poisoned with the Russian nerve agent Novichok

The British government Thursday blamed Russia for the second nerve-agent attack on British soil in four months, and said it is waiting for the Kremlin to call and explain what had happened.

British officials confirmed Wednesday that Dawn Sturgess and Charlie Rowley, who remain in a life-threatening condition, were poisoned with Novichok, the same toxic agent used on former Russian spy Sergei Skripal and his daughter Yulia, in March.

Sturgess and Rowley, who live eight miles from Skripal’s home, had spent the day shopping in Salisbury — similar to Skripal and his daughter — before falling ill Saturday.

“There is no evidence that either the man or woman recently visited any of the sites that were decontaminated following the attempted murders of Sergei and Yulia Skripal,” Neil Basu, Scotland Yard's counterterrorism chief, said in a statement.

An urgent investigation involving more than 100 police officers has been launched to ascertain whether Sturgess and Rowley were targeted specifically or whether they accidentally came into contact with a batch of the nerve agent left over from the Skripal attack.

The government’s emergency Cobra committee is scheduled to meet Thursday, and Home Secretary Sajid Javid is due to make a statement to Parliament soon after.

The incident in Amesbury, Wiltshire will further strain relations between Downing Street and the Kremlin; Moscow is continuing to deny any involvement in either poisoning, calling it a “fake story.”

U.K. security minister Ben Wallace Thursday called on Moscow to explain the incident.

“The Russian state could put this wrong right,” Wallace told BBC Radio 4. “They could tell us what happened, what they did, and fill in some of the significant gaps we are trying to pursue. We have said they can come and tell us what happened. I’m waiting for the phone call from the Russian state. The offer is there.”

Following the Skripal poisoning, the U.K. expelled 23 Russian diplomats and suspended all planned high-level bilateral contacts. In response, Moscow expelled the equal number of U.K. diplomats.

A BBC investigation Wednesday revealed that Russia had been monitoring the Skripals for years before they were poisoned.

After spending Friday afternoon and evening shopping in Salisbury, Sturgess fell ill Saturday morning and was taken to hospital by ambulance. Shortly afterwards, Rowley also began feeling ill.

“His eyes were wide open, glazed, and pin-pricked, and he was sweating, dribbling, and making weird noises,” a friend told the BBC.

It was initially thought that the couple’s illness was caused by taking recreational drugs from a contaminated batch.

READ: Poisoned Russian spy Sergei Skripal survives nerve agent attack

The pair were taken to the Salisbury district hospital, the same place where the Skripals were treated. Due to the concerns about the symptoms, samples were sent to Porton Down — an experimental government laboratory — for analysis.

Experts in chemical warfare announced Wednesday the couple had been poisoned with Novichok, the nerve agent created by the Soviet Union and Russia between 1971 and 1993.

As the incident involves the same rare poison and the same vicinity as the Skripals', it's immediately raised suspicions — but so far there is no conclusive evidence linking the incidents.

Sergey Skripal was targeted due to his links to Russian intelligence. In the case of Sturgess and Rowley, the police said there's no indication they have any links to espionage, suggesting they were poisoned by accident or as a way to confuse investigators.

"The possibility that these two investigations might be linked is clearly a line of inquiry for us," Basu said.

A senior government source speaking to the Press Association Wednesday suggested this was not a follow-up attack but rather a case of cross-contamination. “They [the authorities] have never been able to ascertain the item used to deposit the Novichok, and it’s possible the pair have come into contact with that item,” the source said.

The case could partly hinge on whether the same batch of novichok that poisoned the Skripals was the cause of this incident, but so far Porton Down has not been able to give a conclusive answer to that possibility.

Cover image: Police officers are seen standing guard outside a residential address in Amesbury, southern England, on July 5, 2018 where police reported a man and woman were found unconscious in circumstances that sparked a major incident after contact with what was later identified as the nerve agent Novichok. (CHRIS J RATCLIFFE/AFP/Getty Images)