Attempted murder
A 55-year-old man is in custody.
Jack Ralph is also facing an attempted murder charge after a man was seriously injured in the incident in Kent.
Theresa May announces that an arrest warrant has been issued for two Russian men for the attempted murder of Yulia and Sergei Skripal, with the nerve agent Novichok in Salisbury. British authorities say the two men are officers from the Russian military intelligence service known as the GRU.
The women remain in a critical condition in hospital.
Witnesses have described the harrowing scene.
Scotland Yard said the CPS is treating the case as terrorism.
He was detained on suspicion of attempted murder and serious sexual assault.
A man has been bailed on suspicion of attempted murder.
They have been detained on suspicion of attempted murder.