London, April 17: The nerve agent used to poison former Russian spy Sergei Skripal and his daughter, Yulia, in an English town was delivered in a liquid form, the British Department for Environment, Food and Rural Affairs (DEFRA) said on Tuesday.
A very small amount of the novichok nerve agent was used in the attack and the highest concentration was found at Skripal's house, the Department revealed.
Work to decontaminate sites in Salisbury affected by the nerve agent is beginning, but will take months and involve almost 200 members of the armed forces.
Nine sites have been identified as needing some sort of specialist cleaning, Defra said.
The sites include part of the Maltings shopping centre where Skripal and Yulia collapsed on April 4, the Zizzi restaurant and Mill pub which they visited that day, and the family home on the outskirts of Salisbury.