NEW YORK - Russia's conventional forces are getting bogged down in Ukraine. But in weak-but-resource-rich states, its military diplomacy is becoming more entrenched and unbridled, according to the Wall Street Journal.

This year, Wagner mercenaries have deployed alongside Malian forces across the West African nation's central and northern states. Since March, Russian fighters have been involved in at least six alleged massacres, according to survivors, Western and United Nations officials and human-rights organizations, causing tens of thousands of people to flee across the border to Mauritania.

U.N. investigators, in an unpublished report viewed by The Wall Street Journal, said a joint force of Malian and "white-skinned" fighters raided a group of herders near the border with Mauritania, executing dozens of them.

While the incident took place as part of an operation against jihadists, there was no fighting and the herders were unarmed, survivors told the Journal in interviews.

In several cases, Wagner sent geologists to scout resource-rich regions in southwest and central Mali ahead of its mercenaries, Western security officials said, adding that the timing suggests that Wagner is using military force to clear populations from areas where jihadists operate so that the company can access them for exploration and mining.