A prominent separatist commander in eastern Ukraine was killed when his vehicle was ripped apart by a bomb and then strafed by gunfire, ABC News reported on Saturday.

Reports, citing a prosecutor in the separatist Luhansk region, said Saturday's attack killed commander Alexei Mozgovoi and at least six other people. Prosecutor Sergei Gorenko said the identities of the others were not yet known.

The reports gave no suspected motive for the killing of Mozgovoi, but noted there had been previous attempts on his life.

Mozgovoi was a vocal critic of the Russian-backed separatist leadership. He was one of the Cossacks, members of a semi-military group, who took control of towns in Ukraine's separatist Luhansk region during the uprising against Ukrainian government troops that began a year ago.