The UK is sanctioning 13 individuals and businesses connected to Wagner Group activities in Mali, Sudan and the Central African Republic.
Wagner mercenaries have provided security services in several African countries.
Konstantin Aleksandrovitch Pikalov, sometimes referred to as the “right-hand man” of Wagner chief Yevgeny Prigozhin, is among those named.
He is accused of human rights abuses.
Wagner fighters are also accused by the US of enriching themselves with illicit gold deals on the continent.
Until an attempted mutiny last month, Wagner fighters played a key role in Russian’s invasion of Ukraine.
“The Wagner Group is committing atrocities in Ukraine, as well as acting with impunity in countries like Mali, Central African Republic and Sudan,” UK Development Minster Andrew Mitchell said.
“These sanctions expose despicable individuals who have commissioned violations of international humanitarian law, holding them to account for the severe harm they are inflicting on innocent civilians for financial gain.”