Iraq's self-ruled northern Kurdish region says it has unilaterally started sending its crude oil to Turkey and is going ahead with plans to export oil despite objections by the central government in Baghdad.

According to a statement late Wednesday by the Kurds' regional Natural Resources Ministry, the flow of oil to Turkey started in early January. The oil is being shipped north through a newly constructed pipeline to the Turkish port of Ceyhan, bypassing Baghdad.

The Arab-led government in Baghdad and the ethnic Kurds in the country's north have been locked in a long-running dispute over who is in charge of the country's oil and who has the rights to develop Iraq's natural resources, based on different interpretations of the 2005 constitution.

Baghdad insists it has the sole right to draw plans, award deals to developers and export crude on the international market. Meanwhile, Kurds argue that the constitution allows their regional government to do so as well.

Since the 2003 U.S.-led invasion, the Kurds have unilaterally signed dozens of oil deals with foreign energy companies to tap their vast oil and gas resources, without going through Baghdad. The central Iraqi government maintains that all those deals are illegal. The oil dispute is part of a bigger one involving territory and the allocation of money.

The Iraqi Kurdish ministry has also invited companies to participate in a tender later in January for the 2 million barrels already deposited in Ceyhan. It anticipates an increase in exports to 4 million barrels in February and 6 million barrels in March, with the goal of exporting 10 million to 12 million barrels in December.

Officials in Baghdad were not immediately available for comment on Thursday. But last month, Iraq's Deputy Prime Minister Hussain al-Shahristani, who is in charge of the energy sector, warned that Baghdad would deprive the Kurds of their 17 percent share in the national budget if they go ahead with the exports without the government's approval.

For its part, Turkey has been reluctant to get involved in Iraq's internal oil dispute, but there have been reports that Ankara would not allow the exports without Baghdad's OK. Turkish officials could not be immediately reached for comment on Thursday.