All coverage
Estonian authorities say Russian border guard removed river border markers from Estonian territory
By Nate Ostiller
Escalating Tensions: Russia’s Dispute with Estonia Over Narva River Navigation Buoys
By Huma Siddiqui
Russia Tests NATO With Bold Border Move: ISW
By Kaitlin Lewis
EU wants answers from Russia on 'unacceptable' Estonian border action
By Bart Meijer and Frances Kerry
Russia's 'aggressive' actions sparks World War 3 fears as NATO country urges response
By Alice Scarsi