- The Latest: Lavrov: Britain has no proof in spy poisoningWashington Post
- Russian spy: Moscow vows swift response on expulsionsBBC News
- Russia warns UK it will retaliate soon for expulsion of diplomats over nerve attackReuters
- Nerve agent in our midst is haunting, dangerous — and divisiveCBC.ca
- Russia Promises Reprisals To UK As White House Calls Out Moscow Over Poison AttackNPR