Baghdad - Iraq has called on Turkey to immediately withdrawal Turkish troops operating in the country's north, saying the deployment was a violation of Iraqi sovereignty, the prime minister's office said on Saturday.
Prime Minister Haidar Al-Abadi said the entry of "around one armed battalion" of Turkish soldiers to the northern Nineveh area near Mosul was done without permission.
Mosul is under the control of the Islamic State of Iraq and the Levant (Isil).
The unauthorised presence of Turkish troops in Mosul province is a serious breach of Iraqi sovereignty.
The Iraqi foreign ministry in a statement on state television described the Turkish deployment as "an incursion" and rejected any military operation that was not co-ordinated with the federal government in Baghdad.
A Turkish security official said the troops had been in the Kurdish region of northern Iraq on a training mission since 2014.
An anonymous Turkish security official told Reuters news agency the troops had been in Iraqi Kurdistan and had moved to Mosul accompanied by armoured vehicles - a move that coalition countries targeting Isil were aware of.
Video released on the website of Turkey's pro-government Yeni Safak newspaper showed flatbed trucks carrying armoured vehicles along a road at night, describing them as a convoy accompanying the Turkish soldiers to Bashiqa.
Iraq demands withdrawal
A senior Kurdish military officer based on the Bashiqa front line, north of Mosul, said additional Turkish trainers had arrived at a camp in the area overnight on Thursday escorted by a Turkish protection force.
He said he was not aware of the size of the force and refused to speculate.
The camp is used by a force called Hashid Watani (national mobilisation), which is made up of mainly Sunni Arab former Iraqi police and volunteers from Mosul.
It was formed by former governor Atheel al-Nujaifi, who is close to Turkey. There was already a small number of Turkish trainers there before this latest deployment.
"Our soldiers are already in Iraq. A battalion of soldiers has gone there. Training was already being given in that region for the last two to three years. This is a part of that training," one senior Turkish official said.
In Washington, two US defence officials said on Friday that the US was aware of Turkey's deployment of hundreds of Turkish soldiers to northern Iraq, but the move was not part of the US-led coalition's activities.
Another senior Turkish official said the soldiers in the region were there to train Kurdish Peshmerga fighters.
Turkey has close relations with the Kurdish autonomous zone of northern Iraq, though it views Syrian Kurdish groups across the border as hostile to its interests.
"This is part of the fight against Daesh [Isil]," the Turkish official said, adding there were about 20 armoured vehicles accompanying the force as protection.
Isil occupies swathes of Iraq and Syria, profiting from disunity among groups opposing it.
On Tuesday, the US said it was deploying a new force of special operations troops to Iraq to conduct raids against Isil there and in neighbouring Syria, ratcheting up its campaign against the group.