British Prime Minister Theresa May visited Salisbury on Thursday, the elegant cathedral city that became the unlikely backdrop to a chemical attack against a Russian former double-agent this month.

Dominated by its 13th century cathedral with England's highest spire, Salisbury has witnessed dramatic scenes since the attack as soldiers in chemical suits and gas masks conduct forensic searches.

Dozens of passersby and schoolchildren crowded outside the city's Guildhall to get a view of May as she met emergency service workers, police and local politicians.