Direct proof of use
The public record supports the 120-PM-38 in the 2014 Yemen Civil War as a legacy 120 mm mortar fielded from pre-war Yemeni Army stocks rather than as a newly supplied weapon. Oryx's pre-war Yemeni Army handbook lists the 120mm M-1938 heavy mortar and states that its inventory catalogue covers equipment in Yemeni Army service before the 2014-2015 Houthi takeover and clarifies what military equipment was available to Yemeni parties on the battlefield.
The strongest firing evidence is caliber-level rather than model-level. Human Rights Watch documented mortar attacks by pro-Houthi or Houthi-Saleh forces in Aden and Taizz and identified 120 mm mortar use from remnants, impact evidence, or video analysis. Those reports support 120 mm heavy mortar fire in the conflict, while the Oryx inventory entry supports M-1938/PM-38 availability in the same theater.
Sources: Oryx Pre-War Yemeni Fighting Vehicles, HRW Houthi Artillery in Aden, HRW Artillery Attacks in Taizz
Dated milestones
The relevant chain begins with the 2014-2015 Houthi takeover period. Oryx framed the M-1938 heavy mortar as part of the pre-war Yemeni Army equipment base that became relevant to the battlefield after the takeover, while the UN Panel of Experts reported a pattern of Yemeni Army weapons and military-support diversion to Houthi-Saleh forces.
On July 19, 2015, Human Rights Watch investigated mortar fire into Dar Saad in Aden and reported impact-site and remnant evidence consistent with 120 mm mortars fired from positions held by Houthi forces. In May 2017, Human Rights Watch documented Houthi-Saleh shelling in Taizz and analyzed a May 23 video as showing a 120 mm mortar projectile fired from the east, where Houthi-Saleh forces were positioned.
Sources: Oryx Pre-War Yemeni Fighting Vehicles, UN Panel of Experts Yemen 2016, HRW Houthi Artillery in Aden, HRW Artillery Attacks in Taizz
Use pattern
The documented role is legacy heavy mortar fire support by Yemeni parties, especially Houthi-aligned or Houthi-Saleh forces in the cited firing incidents. The parent catalog row keeps both Houthi-aligned forces and Yemeni government and Saudi-led coalition forces because the weapon source identifies the pre-war Yemeni Army inventory rather than a single faction-specific captured tube.
The evidence should be read with a model-identification boundary. Oryx directly names the 120mm M-1938 heavy mortar in the pre-war Yemeni Army inventory; HRW and UN records directly document 120 mm mortar fire and Houthi-Saleh access to Yemeni Army weapons, but they do not state that the fired 120 mm mortar in a named incident was specifically a PM-38/M-1938 rather than another 120 mm mortar type.
Sources: Oryx Pre-War Yemeni Fighting Vehicles, UN Panel of Experts Yemen 2016, HRW Houthi Artillery in Aden, HRW Artillery Attacks in Taizz