* Turkish foreign minister visits disputed city
* Baghdad says its constitution has been violated
* Neighbours at odds since end of last year
By Barry Malone
BAGHDAD, Aug 3 Iraq made a formal protest to
Turkey's envoy in Baghdad on Friday after the Turkish foreign
minister made a surprise visit to an oil-rich Iraqi city claimed
by both the central government and the country's autonomous
The episode, the latest in a series of diplomatic spats and
tit-for-tat summonings of envoys between the neighbouring
countries, is likely to worsen already strained relations.
Turkish Foreign Minister Ahmet Davutoglu had travelled to
Kirkuk on Thursday after visiting the regional president in
Arbil, the capital of Iraqi Kurdistan.
But Iraq's foreign ministry accused Turkey of violating its
constitution with the visit, saying that Davutoglu had neither
asked for nor obtained permission to enter Kirkuk.
A junior minister at Iraq's foreign ministry had handed
Turkey's charge d'affaires a protest letter on Friday, a
strongly-worded statement from the foreign ministry said.
"The note also included a demand by the Iraqi government
(for an) urgent explanation from the Turkish government," it
Relations between Iraq, close to Shi'ite Iran, and Sunni
Muslim regional power Turkey, were tested after U.S. troops
pulled out of Iraq last year and the government immediately
tried to arrest one of its Sunni vice presidents.
He fled first to Kurdistan and later to Ankara, where he was
Iraqi Prime Minister Nuri al-Maliki and Turkey's Prime
Minister Tayyip Erdogan then traded public insults.
Baghdad's Arab-led central government and ethnic Kurdish
officials are locked in a protracted dispute over who controls
territory and oilfields along their internal border. Kirkuk,
which possesses huge crude oil reserves, is one of those areas.
Iraq and Turkey are also at odds over the worsening conflict
in Syria. Turkey has become one of the main backers of the
rebels, while Baghdad has refused to support calls for President
Bashar al-Assad to step aside.
Iraq is Turkey's second largest trading partner after
Germany with trade reaching $12 billion last year, more than
half of which was with the Kurdish region.
(Editing by Andrew Osborn)