Spy poisoning: Rudd chairs Cobra meeting as military deployed in Salisbury

Home Secretary Amber Rudd is chairing an emergency meeting of the Government's Cobra committee following the nerve agent attack on ex-Russian spy Sergei Skripal and his daughter in Salisbury.

Downing Street said investigators had been summoned to provide updates on the case at 3pm on Saturday.

Around 180 troops, including Royal Marines, RAF personnel and chemical specialists, have been deployed in Salisbury to help police with their investigation, as attention moved to the burial site of Mr Skripal's wife and son.

Scotland Yard requested specialist help to remove vehicles and objects from scenes across the city amid fears of contamination.

Officers in hazmat suits were sent to Salisbury's London Road cemetery, where a tent was erected over the memorial to Mr Skripal's son Alexander, who was cremated last year.

Officers also sealed off the gravestone of Mr Skripal's wife Liudmila, who was buried there in 2012.

Police say their deaths are part of the investigation into the poisoning of Mr Skripal, 66, and his daughter Yulia, 33, who were found slumped on a park bench in Salisbury on Sunday evening.

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They remain in a serious condition in hospital, along with detective sergeant Nick Bailey, who was also exposed to the nerve agent.

Sky News Crime Correspondent Martin Brunt said police believe all three victims may have been contaminated at Mr Skripal's house in Salisbury and "ingested the poison some hours before they were taken ill".

Mrs Rudd, who visited the city centre and hospital where DS Bailey is being treated, warned the Government was "committed to doing all we can to bring the perpetrators to justice - whoever they are and wherever they may be".

Russia's foreign minister said the country would consider helping UK authorities investigate the poisoning after the Kremlin denied involvement.

Sergei Lavrov seemed to resent suggestions that Moscow was behind the nerve agent attack on the Skripals, calling such claims "propaganda".

Salisbury's MP John Glen has sought to reassure his constituents that a "whole range of tools are at our disposal" once it is established who was behind the poisoning.

Mr Glen was responding to some locals who had demanded "decisive action" over the incident.

The Economic Secretary to the Treasury said in a Facebook post: "Now is the time for cool heads and a rational examination of the facts.

"Once these are established, then, and only then, will an appropriate and proportionate course of action be taken. A whole range of tools are at our disposal depending on who has perpetrated this act, including a number of financial and economic levers."

Skripal served four years of a 13-year sentence in Russia after he was caught spying for MI6 and was released as part of a spy exchange in 2010, when he was given refuge in the UK.

The circumstances of the attack, and its echoes of the fatal poisoning of Alexander Litvinenko in 2006, have prompted questions over the Government's response if the evidence points to a state-sponsored assassination plot.