By Stephen Kalin and Asli Kandemir
BAGHDAD/ANKARA (Reuters) - Gunmen in military uniform seized 18 Turkish workers from a sports stadium they were building in northeastern Baghdad on Wednesday, their company said, in what Ankara said appeared to have been a targeted attack.
Diplomats have said Turkey could suffer reprisals after abandoning months of reticence to launch air strikes against Islamic State in neighbouring Syria and open its bases to a U.S.-led coalition fighting the Sunni Muslim militants.
The workers were taken in the predominantly Shi'ite district of Habibiya, Iraqi Interior Ministry spokesman Brigadier General Saad Maan said.
There was no immediate claim of responsibility, but Turkish Deputy Prime Minister Numan Kurtulmus said investigators in both countries were cooperating.
"People dressed in military uniforms broke down the door at 3 a.m. (midnight GMT) and abducted all these people," said Ugur Dogan, chief executive of Nurol Holding, which owns the construction firm.
Last year, 46 Turkish citizens were seized by Islamic State militants in the Iraqi city of Mosul. They were released unharmed after more than three months in captivity.
Islamic State regularly claims suicide bomb attacks in Baghdad, but Shi'ite militias and other armed groups are also active there.
The Shi'ite-led government in Baghdad has intensified security in the city this week ahead of plans to ease access to the fortified Green Zone and eliminate no-go zones set up by militias and political parties.
Two police sources said the gunmen had arrived in a convoy of black sports utility vehicles. Maan denied reports that up to three Iraqis had also been abducted, and put the number of people kidnapped at 16.
A spokesman for the Turkish foreign ministry said Turkish nationals had been specifically picked out by the attackers, without giving further details.
An Islamic State video released last month accused Turkish President Tayyip Erdogan of "selling the country to crusaders" and of allowing U.S. access to Turkish bases "just to keep his post".
Kurtulmus also said no contact had been established with a Turkish soldier who went missing late on Tuesday following cross-border fire from Islamic State-held territory in northern Syria, which left one other soldier dead.