What is Russia's Wagner Group of mercenaries in Ukraine?
British military intelligence says 1,000 mercenaries from the Russian private military company, the Wagner Group, are being deployed to eastern Ukraine.
The group has been active over the past eight years in Ukraine, Syria and African countries, and has repeatedly been accused of war crimes and human rights abuses.
How was the Wagner Group started?
A BBC investigation into the Wagner Group has pointed to the believed involvement of a 51-year-old former Russian army officer, Dmitri Utkin. He is thought to have founded Wagner and given it its name - his own...