Russia has delivered four attack helicopters to the Iraqi air force to assist in Baghdad's struggle against Islamic State militants, the Interfax news agency reported citing a Russian military source.
The Mi-28 Night Hunters were delivered on Sunday, the source said, as part of a 2012 agreement for the supply of 40 Mi-28 and Mi-40 military helicopters. The $4.2 billion contract also covers the delivery of 42 anti-aircraft systems.
Russia has been ramping up support for the Iraqi government in its struggle to contain Islamic State, which has conquered large swathes of Iraq and Syria.
The Mi-28s began arriving in Iraq in January last year. The last delivery took place in September.
In July, Russia delivered five Su-24 ground attack aircraft worth an estimated $500 million to help in the fight, according to the BBC.