A former Russian spy and his daughter were poisoned by a nerve agent in a "targeted" act, British authorities revealed Wednesday.
Metropolitan Police Assistant Commissioner Mark Rowley said a police officer who came into contact with the substance that sickened Sergei Skripal, 66, and his 33-year-old daughter, Yulia, also fell ill, collapsed, and is in "serious condition." All three are in comas, Sky News reported.
Rowley said authorities are "working closely with a wide range of specialists" to determine the exact nerve agent involved.
Rowley stressed that while police are treating the poisoning as an attempted murder, they have no evidence of a widespread threat to others. Chief medical officer Sally Davies told reporters the poisoning posed a "low risk" to the general public.
"Our role now is to find out who is behind the attacks," Rowley told reporters, adding that authorities as asking for the help from the public as they build a timeline of events of what led up to the poisoning. The Met Police said in a news release they are appealing to anybody who visited Salisbury town center and surrounding areas on Sunday for more information.
Home Secretary Amber Rudd said earlier in the day it was important to respond to evidence, not rumors. Rudd's comments came after she chaired a meeting of the government's emergency committee, known as Cobra, Sky News reported.
"There is a lot of information about him but I am not going to comment further about that," she said.
Her comments came as Russian officials said the case was being used to fuel an "anti-Russian campaign" and further strain ties with Britain.
"What happened to Skripal has been immediately used to further incite an anti-Russian campaign in Western media," Russian Foreign Ministry spokeswoman Maria Zakharova said.
Skripal, a former colonel in Russia's GRU military intelligence service, was convicted in 2006 of spying for Britain and imprisoned. He was freed in 2010 as part of a widely-publicized spy swap in which the U.S. agreed to hand over 10 members of a Russian sleeper cell found operating in America in return for four Russians convicted of spying for the West.
He and his daughter were found collapsed on a bench near a shopping mall Sunday in the town of Salisbury, 90 miles southwest of London.
On Wednesday, a Russian politician said that Skripal "wasn't interesting" to the Kremlin and he doesn't believe in Russian involvement in the alleged poisoning.
In an interview with Sky News, Andrei Lugovoi said Skripal had already served his time after being convicted in 2006 of spying for Britain and had been pardoned by the Russian president.
"I think that in this case, considering the rules of the Secret Services, the incident was over and done with," Lugovoi said.
Foreign Secretary Boris Johnson told lawmakers Tuesday that if Moscow is shown to have been involved in the Skripal case, the government would act — possibly downgrading England's participation in this year's soccer World Cup in Russia. Johnson warned British officials may not be involved in the sporting event "in the normal way," but did not elaborate.
Police, fire and ambulance crews arrived outside Zizzi's restaurant in Salisbury on Wednesday close to the location where Skripal and his daughter were found as the investigation continues, according to Sky News.
A woman with dark hair was seen being taken out of Sarum House, next door to the pizzeria, and driven away in an ambulance.
A spokeswoman for South Western Ambulance Service told Sky News she was aware of what was happening, but added: "I'm sorry, we can't give anything out about that one."
CCTV has emerged of Skripal buying milk and bacon at a shop in Salisbury days before he and his daughter were found collapsed, Sky News reported.
While police say they are keeping an open mind about the case, it has reminded Britain of the 2006 poisoning of former spy Alexander Litvinenko.
A British inquiry into his death found that Russian agents poisoned him by lacing his tea with radioactive polonium-210 and that the killing was probably approved by President Vladimir Putin. Russia has denied any involvement in Litvinenko's death, and this week said it wasn't involved in Skripal's collapse.
Litvinenko's widow, Marina, wrote Wednesday in the Times of London that her husband's case made clear to Britain's emergency services that they need to act quickly when "someone suddenly falls mysteriously ill."
"I am happy my story has raised awareness about the potential danger posed by Moscow, and this could help to save somebody's life," she wrote in an opinion piece.
The Associated Press contributed to this report.