An Iraqi soldier was gunned down overnight as security forces reportedly closed in on a gang member suspected of kidnapping 18 Turkish construction workers in the Iraqi capital of Baghdad.

Unidentified gunmen attired in military uniforms seized the workers before dawn on Wednesday as they slept near the site of a sports stadium they were building in the northeastern Shiite district of Habibiya, according to authorities. The abductors drove the men away in black SUVs, police said.

No groups have come forward to claim responsibility for the kidnapping, which the Turkish government believes was a targeted operation directed at its countrymen. Iraqi and Turkish authorities are working together to investigate the crime and find the abductees.

The Iraqi soldier was killed overnight after intelligence information led forces to "one of the members of the gang that carried out the kidnappings" on a Baghdad street, the city's security command said.

"Forces moved to search and inspect in Palestine Street, but were fired on by armed men who tried to intercept them, resulting in the martyrdom of a soldier and the wounding of three others," the unidentified security official explained, according to AFP.

Local media affiliated with Ketaeb Hezbollah, a powerful Iranian-backed Shia militia, reported that the Baghdad Operations Command had targeted the group's headquarters on Palestine Street when the soldier was shot. Iraqi security sources and officials backed up those claims on Friday, according to Reuters.

While members of Ketaeb Hezbollah have joined Iraqi forces in fighting the so-called Islamic State (IS) insurgency, the government has not been able to prevent some militias from breaking away from government command and acting on their own.

Some Shia militia fighters working alongside Iraqi forces have been accused of thefts, kidnappings, and murder, among other crimes. On Wednesday, Iraqi Prime Minister Haider al-Abadi blamed the abductions on "corrupt and organized criminals," but did not name a specific group.

Political motives for the kidnappings also cannot be ruled out, particularly because Turkey recently abandoned its long-held resistance to conducting airstrikes against IS targets.

IS has abducted dozens of Turkish citizens in the region since it began its bloodied land grab across large parts of Iraq and Syria last summer. Last year, IS fighters took 46 Turkish citizens captive in Iraq's second largest city of Mosul. The militants later released the abductees unharmed more than three months after their capture.

Despite Turkey's new commitment to fighting extremists by complementing the efforts of a US-led coalition, it has been criticized for its hesitant response to the IS threat. The government is opposed to arming and training Kurds battling IS along Turkey's border with Syria out of fear that they will align with the Kurdistan Workers' Party, known as the PKK, which has waged an armed campaign for an independent Kurdish state since 1984 in the area where Turkey, Syria, and Iraq meet. Turkey, NATO, and the United States have classified the PKK as a terrorist organization, and Turkish forces have bombarded PKK installations while also striking at IS.

Turkey has meanwhile begun supporting Sunni rebels fighting forces loyal to Syrian President Bashar al-Assad. Some Shia militias, notably Lebanon's Hezbollah, are helping to support the Syrian government, which is closely allied with Iran.