Direct proof of use
The FN Minimi family is represented in the 2001 War in Afghanistan by the U.S. M249 Squad Automatic Weapon. A DVIDS image record from 21 March 2019 documents a Task Force Iron Eagles crew chief manning an assigned M249 as a UH-60 Black Hawk crossed the Combined Joint Operations Area in Afghanistan in support of Operation Freedom's Sentinel and Resolute Support.
Earlier U.S. military reporting also places the M249 with Marine units in Afghanistan. A 2012 DVIDS story from Forward Operating Base Sabit Qadam described the M249 Light Machine Gun, formerly the Squad Automatic Weapon, as a weapon being replaced in Marine infantry squads by the Infantry Automatic Rifle while Marines of 2nd Battalion, 7th Marines were deployed in Afghanistan.
Sources: DVIDS Iron Eagles Fly, DVIDS M249 Marines Afghanistan
Timeline
In March 2008, U.S. Army reporting from Forward Operating Base Fenty in Nangarhar Province described Afghan National Army mechanics training with American small arms, including the M249, as part of maintenance instruction with U.S. soldiers.
In May 2012, an Army article on lightweight machine-gun assessment described the M249 SAW as the machine gun then currently used in Afghanistan. In November 2012, DVIDS reported from Forward Operating Base Sabit Qadam that Marine infantry units in Afghanistan were transitioning automatic-rifle roles away from the M249. In March 2019, DVIDS documented an assigned M249 in use by a Task Force Iron Eagles UH-60 crew chief during Operation Freedom's Sentinel and Resolute Support.
Sources: Army Afghan Mechanics M249, Army LSAT M249 Afghanistan, DVIDS M249 Marines Afghanistan, DVIDS Iron Eagles Fly
Operational role
The best-supported Afghanistan role for this detail page is automatic fire support and force protection with U.S.-led forces. The 2019 DVIDS record identifies an M249 assigned to a UH-60 crew chief, tying the weapon to aviation crew security during the post-2015 Operation Freedom's Sentinel and NATO Resolute Support phase of the war.
Public budget material also indicates M249 support for Afghan security forces. The fiscal year 2016 Afghanistan Security Forces Fund justification listed M249 Squad Automatic Weapon funding under Afghan National Army weapons equipment for fiscal year 2014. The fiscal year 2020 justification said Afghan Special Security Forces required sustainment repair parts for M249 light machine guns and other weapons used for counterinsurgency operations. Those documents support transfer, sustainment, and force-equipment context, while the DVIDS image record is the clearest public source here for a specific M249 being manned in Afghanistan.
Sources: DVIDS Iron Eagles Fly, FY2016 ASFF Justification, FY2020 ASFF Justification