pan.bg
Source: dvidshub.net

U.S. Army Soldiers from the 1st Cavalry Division and 20th Engineer Brigade participate in a live fire exercise with Bulgarian and Georgian Soldiers during Balkan Sentinel 21 at Novo Selo Training Area, Bulgaria, May 30, 2021.
Balkan Sentinel 21 is a linked exercise of DEFENDER-Europe 21, which involves special operations activities, air assaults, and live fire exercises in Estonia, Bulgaria, and Romania, demonstrating airborne interoperability among NATO allies and partners.
DEFENDER-Europe 21 is a large-scale U.S. Army-led exercise designed to build readiness and interoperability between the U.S., NATO allies and partner militaries. This year, more than 28,000 multinational forces from 26 nations will conduct nearly simultaneous operations across more than 30 training areas in more than a dozen countries from the Baltics to the strategically important Balkans and Black Sea Region

Video: https://www.dvidshub.net/video/799385/balkan-sentinel-multi-national-lfx-bulgaria-30-may