More than 5,000 soldiers are taking part in Estonia's annual military exercise. These include 1,000 allied NATO troops from 11 countries. The "Spring Storm" exercise is being held in Rapina, a town 30 kilometres from the Russian border.

Latvian Chief of Defence Lieutenant General Raimonds Graube described Russia's leadership as "unpredictable" and believes NATO is simply acting accordingly. He added that the Spring Storm exercise was minor compared to drills Russia regularly hosts along its Baltic borders.

"Spring Storm" is Estonia's defence forces' largest training exercise this year and will continue through to May 20th. The US, Germany, the Netherlands, the UK, Latvia and Lithuania are among the 11 countries participating in the drill.