The Telegram-based investigative news outlet Baza has reported that four officers from the Special Operations Center of Russia’s Federal Security Service (FSB) have been killed near Aleppo, Syria. Baza claimed that a vehicle carrying the officers rode over a land mine, and a group of armed fighters subsequently shot the wounded troops.

Baza wrote that the four officers worked in the S and K divisions of the FSB; it published their ranks and first names. Another Telegram channel, The Special Operations Channel, published three names in full: Captain Dmitry Minov, Major Bulat Akhmatyanov, and Lieutenant Vsevolod Trofimov. That information matches Baza’s with the exception that the latter also named a Major Ruslan G. The Conflict Intelligence Team, a Russian-language investigative group, said that major’s surname was Gimadiyev.

The FSB branch for the Tambov region confirmed Trofimov’s death to Kommersant. All four officers were allegedly killed on February 1, but that date has not been confirmed.