Latest: Watchdog asked to verify Britain's findings on Salisbury nerve agent attack

Latest: Britain has asked the international chemical weapons watchdog to verify its findings that Moscow is behind the nerve agent attack in Salisbury.

Update 10.08pm: Britain has asked the international chemical weapons watchdog to verify its findings that Moscow is behind the nerve agent attack in Salisbury.

The news came after British Prime Minister Theresa May confirmed the UK will expel 23 suspected Russian spies over the incident.