More than 3,000 troops are taking part in "Operation Joint Warrior" in and around Galloway Forest in Dumfriesshire.
A group of British and French paratroopers are also carrying out a parachute drop near to the Braid Fell area.
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77-year-old Derrick Cooper was sentenced at Carlisle Crown Court today for abusing two boys at Underley Hall in Kirkby Lonsdale.
Hundreds of runners will gather at Windermere tonight to run 3.7miles in memory of Matt Campbell.
Arriva Rail North, Greater Anglia and South Western Railway are all affected.