United Kingdom police have expanded their investigation of the nerve-agent poisoning of Russian ex-spy Sergei Skripal and his daughter in the city of Salisbury and confirmed that hospitals have treated 21 people since the pair were found unconscious on Sunday.
Police also extended the cordon around the modest suburban home of Sergei Skripal in Salisbury, as Home Secretary Amber Rudd visited the city, calling the attack "outrageous".
The Home Office has said it knows what kind of nerve agent was used, but has refuse to disclose the information.
Mr Skripal and Yulia, 33, are still in a "very serious" condition five days after they were discovered slumped on a bench in the city centre.
Around 180 troops, including Royal Marines, RAF Regiment troops and chemical warfare specialists, are understood to have been deployed after Scotland Yard requested specialist help to remove vehicles and objects from scenes scattered across the city amid contamination fears.
The UK is preparing retaliatory measures if it's shown that Russian Federation was responsible for the attack on Skripal who had settled in Salisbury, southern England after a spy swap in 2010.
DS Bailey's statement comes as troops descended on Salisbury for a second day, with their focus turning to an ambulance station. Skripal, a former Russian military intelligence officer, was convicted in 2006 of spying for Britain and released in 2010.
A military convoy arrived at the small building close to Salisbury District Hospital and police cordoned off a road.
Russian Foreign Minister Sergey Lavrov said Moscow was "ready to consider" lending a hand, "whether it's poisoning of some British subjects, whether it's rumours about interference in the USA election campaign". "Identifying a rare nerve agent is like identifying exotic food on your plate", said Malcolm Sperrin, a medical physics expert.
Many British media reports and some politicians have suggested a probable link to the Russian government. Officers were guarding the area where he and his daughter were found, along with a pizza restaurant and a pub they had visited.
The U.K. has vowed to take strong action against whoever is responsible for the "brazen and reckless" attack.
Skripal's daughter is thought to be one of the few members of his immediate family still alive after his wife, Lyudmila, and son Alexander died in recent years.
However, he said, "there are not 101 likely offenders", apparently a reference to the difficulty in producing nerve agent, which would limit the number of suspects with the ability to carry out the attack. However, he was delivered to the U.K.in 2010 after a spy swap. Police have sealed off both graves, the UK's Press Association reported, but it was unclear on Friday why.
Sergei Skripal until 1999, was a Colonel in the GRU - the foreign intelligence body of the Ministry of defense of Russian Federation.
In his comments to parliament, Johnson said the Salisbury chase had "echoes" of the plight of former Russian spy Alexander Litvinenko, who died a slow death after drinking tea laced with highly radioactive polonium-210 in 2006 in a hotel in London.
He told Sky News: "Regardless of whether the Russians are involved in this case, they are fighting a new Cold War against us and you need to wisen up to that fact". His condition doctors assessed as "serious but stable".