Direct proof of use
Small Arms Survey transfer data for Afghanistan lists M721 60 mm illumination cartridges with M776 fuzes in Afghan National Army ammunition records. The dataset records a 6,000-cartridge line under "Ammunition for the ANA" implemented on November 6, 2009, and an 8,640-cartridge line under "Sustainment Ammunition" implemented on March 8, 2010.
That evidence places the M721 in Afghan government ammunition channels during the war. It documents supply and sustainment accounting rather than a specific mortar unit, location, or firing incident.
Sources: Small Arms Survey Afghanistan Arms Transfers Dataset
Timeline
The documented Afghanistan record is concentrated in U.S.-origin ammunition transfer data for the Afghan National Army. The first cited M721 line appears in November 2009, followed by a sustainment-ammunition line in March 2010.
Sources: Small Arms Survey Afghanistan Arms Transfers Dataset
Narrative
The M721 is a visible-light 60 mm illuminating mortar cartridge. FAS describes it as a cartridge intended to illuminate target areas for fire adjustment, using an illuminant candle and parachute assembly, with an M776 mechanical time fuze and about 300,000 candlepower of light.
In Afghanistan, the conflict-specific evidence is administrative rather than tactical. The Small Arms Survey dataset identifies Afghan National Army ammunition lines containing M721 cartridges with M776 fuzes, connecting the round to the United States, NATO, and Afghan government side of the conflict. The available public record does not establish whether the listed cartridges were fired in combat, retained in stock, expended in training, or later captured.
Sources: M721 60mm Illuminating Mortar Cartridge, Small Arms Survey Afghanistan Arms Transfers Dataset