Exclusive - Russian private security firm says it had armed men in east Libya

FILE PHOTO: General Khalifa Haftar, commander in the Libyan National Army (LNA), leaves after a meeting with Russian Foreign Minister Sergei Lavrov in Moscow, Russia, November 29, 2016. REUTERS/Maxim Shemetov/File Photo

MOSCOW (Reuters) - A force of several dozen armed private security contractors from Russia operated until last month in a part of Libya that is under the control of regional leader Khalifa Haftar, the head of the firm that hired the contractors told Reuters.

It is the clearest signal to date that Moscow is prepared to back up its public diplomatic support for Haftar -- even at the risk of alarming Western governments already irked at Russia's intervention in Syria to prop up President Bashar al-Assad.