The Yemeni Government has reported that a hoard of Axumite (Ethiopian) and late Roman gold coins previously in the inventory of the Aden Museum were stolen during the ongoing civil war.
The coins are further described in a publication entitled, STUART MUNRO-HAY, The al-Madhāriba Hoard of Gold Aksumite and Late Roman Coins, The Numismatic Chronicle (1966-) Vol. 149 (1989), pp. 83-100 (available at https://www.jstor.org/stable/42667572?seq=1#page_scan_tab_contents).
Furthermore, the Antiquities Coalition, an archaeological advocacy group, is also publicizing this loss. See https://theantiquitiescoalition.org/uncategorized/publics-help-needed-to-recover-blood-antiquities/ (see linked publication at pages 117-144).
You should contact national law enforcement authorities if you are offered any of these coins.