Direct proof of use
The MT-12 Rapira appears in the Yemen record through September-October 2018 reporting rather than through a declared procurement or official transfer notice. Rossiyskaya Gazeta reported on 18 September 2018 that 100 mm MT-12 Rapira anti-tank guns had been seen in recent fighting in Yemen, even though reference sources did not list the type as part of Yemen's known inventory.
Sputnik Arabic followed on 9 October 2018 with a report on a destroyed Rapira gun in Yemen. The article embedded and cited a Yemen Observer post saying Amaliqa forces captured weapons from Houthi forces on the outskirts of Hays and destroyed an MT-12 gun; Sputnik added that the destroyed gun had been hit by a powerful munition and that an Arab coalition unit had destroyed it.
Sources: Deadly Rapira Guns First Noticed in Yemen Combat Zone, Powerful Round Destroys Rapira Gun in Yemen
Timeline
On 18 September 2018, Rossiyskaya Gazeta reported the first noticed appearance of MT-12 Rapira guns in Yemen's combat zone, placing the sightings in recent civil-war fighting without identifying a precise unit or transfer channel.
On 29 September 2018, the Yemen Observer post later quoted by Sputnik described Amaliqa forces on the outskirts of Hays capturing weapons from Houthi forces and destroying an MT-12 gun. Sputnik's 9 October article used that report and accompanying imagery as the basis for its account of the destroyed Rapira.
Sources: Deadly Rapira Guns First Noticed in Yemen Combat Zone, Powerful Round Destroys Rapira Gun in Yemen
Narrative
The sourced Yemen evidence supports a narrow role for the MT-12: a towed 100 mm gun used or at least fielded in ground fighting, with Houthi-held equipment documented in the Hays area and destroyed or captured by coalition-aligned forces. The sources do not establish how many guns were present, whether they came from prewar Yemeni stocks, battlefield capture, or a later transfer, or whether the destroyed gun had fired during the specific Hays incident.
Rossiyskaya Gazeta noted that older 100 mm BS-3 and 85 mm D-44 guns had been associated with Yemen, while the MT-12 was not normally listed there, and suggested either an unrecorded prewar Yemeni holding or a recent movement into the theater as possible explanations. That makes the Yemen Rapira record best treated as documented battlefield appearance and limited operational use, not as proof of a broader supply chain or inventory size.
Sources: Deadly Rapira Guns First Noticed in Yemen Combat Zone, Powerful Round Destroys Rapira Gun in Yemen