The scene was later covered by a forensic tent.
Skripal was jailed in Russian Federation in 2006 for selling state secrets to the British intelligence services but was released in 2010 as part of a high-profile spy swap. The 66-year-old former agent had been living quietly in Salisbury, 90 miles southwest of London.
Speaking to reporters during a visit to the African Union headquarters in Addis Ababa on Friday, Lavrov said Russian officials had not received a single fact or piece of concrete evidence about what had happened to Skripal and his daughter.
About 180 troops including some with chemical expertise had been sent to the city to remove ambulances and other vehicles involved in the incident and other objects, Britain's ministry of defence and police said.
"Nick would like us to say on his behalf that he and his family are hugely grateful for all the messages of support from the public, and colleagues from the police family", the police department said.
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.
Detectives were retracing the Skripals' movements as they try to discover how the toxin was administered and where it was manufactured.
Officers also sealed off the gravestone of Mr Skripal's wife Liudmila, who was buried there in 2012.More news: Judge Urges Trump To Mute, Not Block, Twitter Critics
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Their son Alexander died aged 43 in mysterious circumstances in St Petersburg a year ago.
A day earlier, a presenter on Russia's Channel One news program struck a different tone, saying - without mentioning names - that the poisonings should serve as a warning to Russians considering betraying their country.
"There may be some clues floating around in here", Blair said.
"A well-equipped lab and a very experienced analytical chemist can do it, but it's not the sort of thing a chancer doing kitchen-sink chemistry can get away with", said chemical weapons expert Richard Guthrie.
Bob Seely, a Conservative lawmaker and member of the foreign affairs select committee, said the United Kingdom should be cautious about apportioning blame but said circumstantial evidence did raise suspicions of Russian involvement.
"We're accused not only of this, but we are accused of everything that goes wrong on this planet, according to our Western partners", Lavrov said. "Military assistance will continue as necessary during this investigation".
Prime Minister Theresa May has said Britain will react with the appropriate response if a state was found to be behind the murder attempt.
A Downing Street spokesman declined to comment on what sanctions might be taken against Russian Federation if it was shown to be responsible for the Salisbury attack.
Yet as the Post adds, British authorities attached strong words to their suspicions.
Information for this article was contributed by Danica Kirka and Jim Heintz of The Associated Press.