The opening salvo of the Estonian component of a large-scale United States military exercise came in the form of Multiple Launch Rocket System (MLRS) live-firing at an exercise involving personnel from both countries, along with the United Kingdom, Wednesday. Thursday evening saw a large scale United States airborne jump over central Estonia. The live firing took place at the Estonian Defense Forces' (EDF) Central Polygon training area in Harju County, part of Exercise Swift Response, which in turn is a subset of the U.S. DEFENDER-Europe 21 exercise. Exercise Swift Response continued Thursday evening with the airborne drop over Nurmsi airfield in Järva County, which saw hundreds of U.S. airborne personnel making a jump.