LONDON (AP) — Britain sanctioned Russia’s GRU intelligence agency and summoned Moscow’s ambassador on Thursday after an inquiry concluded that President Vladimir Putin was responsible for a nerve agent attack on British soil in 2018.

The government said that GRU was being sanctioned in its entirely over the attack in the city of Salisbury that targeted Sergei Skripal, a former Soviet agent who had defected to Britain.

Skripal and his daughter Yulia became seriously ill, but survived.

A British woman, Dawn Sturgess, and her partner collapsed after they came into contact with a discarded perfume bottle containing the nerve agent Novichok. She had sprayed the contents of the bottle on her wrist and died days later. Her partner survived.

Former U.K. Supreme Court Justice Anthony Hughes, who led an inquiry into Sturgess’ death, said that the attack on the Skripals “must have been authorized at the highest level,” by Putin.

He concluded that Sturgess was “an innocent victim of an attempt by officers of a Russian state organization to conduct an assassination on the streets of Salisbury using a highly toxic nerve agent.”

Moscow has denied any role in the attack.