Russian state-run media outlets have reportedly deleted their overnight coverage of new casualty numbers among private Russian troops in Syria.

Up to 300 Russian mercenaries attempting to take over a Syrian oil refinery were killed or injured in U.S. airstrikes on Feb. 7, the Reuters news agency reported on Thursday. A Russian military doctor cited by the news agency estimated that around 100 Russian soldiers were killed in total.

Several Russia-based journalists reported that the Vesti.ru state news website covered the Reuters report early on Friday before later deleting the story. Cached versions of the article show Vesti.ru’s report published early Friday being shared on Facebook and Russian social media.

On Thursday, the Foreign Ministry admitted for the first time that five Russian citizens “could” have been killed in the clashes. Maria Zakharova, the ministry's spokeswoman, dismissed reports of higher losses as “classic disinformation.”

The Kremlin has maintained that no formal Russian military personnel have been killed in the clashes with U.S.-led forces.

The open-source Conflict Intelligence Team investigative group, meanwhile, has named nine Russian Wagner fighters who were killed in the Feb. 7 attack in Syria.