The Russian government has been consistently under-reporting their casualty figures from the Syrian Civil War, a Reuters investigation has found.

After a combined effort from Reuters and the Conflict Intelligence Team investigative group, researchers found that Russian casualties were actually three times the amount of what was being officially reported by the Russian government, and that many of the deaths were from private military contractors.

As a whole, Russia has been largely quiet about combat casualties this year. The independent investigation, which verified each combat casualty by speaking to family members and friends of each deceased soldier, confirmed a rapid uptick in casualties coinciding with the second offensive to retake the city of Palmyra.

The Syrian Army, with the assistance of Russian regulars and paramilitaries, retook the ancient city earlier this month.