Iraqi security officials have said the country has received the first batch of fighter jets that it had ordered from Russia to help battle gains by a militant group, BBC News reported on Dunday.

According to the report, the officials said “five second-hand Sukhoi attack aircraft would enter service within a few days, and that more were on their way.”

Iraq has been fighting an offensive by insurgents from the Islamic State of Iraq and Syria, or ISIS. The militant group has gained control of large swathes of the north and west of Iraq after a string of attacks this month.

On Saturday, the government said it had retaken the northern city of Tikrit, which on June 11 fell to the ISIS militants.

ISIS is a more radical offshoot of al-Qaeda that has its roots in Iraq and expanded into Syria shortly after the start of the three-year insurgency against President Bashar al-Assad.

The military gains by Islamic State fighters have highlighted the extent to which the conflict in Iraq is intertwined with the civil war in Syria, where more than 160,000 people have been killed in the last three years.

Iran is ready to help Iraq fight an armed revolt using the same methods it deployed against opposition forces in Syria, an Iranian general said, suggesting Tehran is offering to take a larger role in battling Sunni militias threatening Baghdad.

Iraq’s million-strong army, trained and equipped by the United States, largely evaporated in the north after Sunni fighters led by ISIS launched their assault with the capture of the north’s biggest city Mosul on June 10.

Iran is secretly flying surveillance drones over Iraq and sending military equipment there to help Baghdad in its fight against Sunni insurgents, The New York Times reported Wednesday.

A "small fleet" of Ababil drones was deployed to the Al Rashid airfield near Baghdad, the newspaper said on its website, citing anonymous U.S. officials.

Al Arabiya