In a statement on its website, Islamic State said its fighters had killed scores of Kurdish fighters. "Hundreds fled leaving vehicles and a huge number of weapons and munitions and the brothers control many areas," Islamic State said. "The fighters arrived in the border triangle between Iraq, Syria and Turkey," it said.

Islamic State, which changed its name earlier this year from the Islamic State in Iraq and the Levant (ISIL), has stalled in its drive to reach Baghdad, halting just before the town of Samarra, 62 miles north of the capital.

Islamic State has capitalized on Sunni disenchantment with Maliki. Critics say Maliki as put allies from the Shia majority in key military and government positions at the expense of Sunnis, driving a growing number of the religious minority in Iraq to support the Islamic State and other insurgents. He is also at odds with the Kurds.

The Kurds have long dreamed of their own independent state, an aspiration that has angered Maliki, who has frequently clashed with the non-Arabs over budgets, land and oil. After the Islamic State arrived, Kurdish forces seized two oil fields in northern Iraq and took over operations from a state-run oil company, complicating the task of trying to hold the country together.

A Kurdish oil tanker hoping to deliver its crude in Texas has become a source of contention between the U.S. and Baghdad, with Iraq’s government filing a complaint to the state of Texas claiming the oil was smuggled out of the semi-autonomous region. Kurdistan has said the oil is completely legal.

A U.S. judge initially issued an order to seize the 1-million-barrel United Kalavrvta tanker, but later she said she didn’t have the jurisdiction because of its distance from shore.

Al Jazeera and Reuters