Reports say Al-Qaeda-linked militants have seized the Turkish consulate in the northern Iraqi city of Mosul and kidnapped members of the diplomatic mission.
Western news agencies quoted a Turkish government source as saying on June 11 that insurgents from the Islamic State in Iraq and the Levant (ISIL) kidnapped around 45 people, including the Turkish consul, consulate staff members, members of Turkey's special forces, and several children.
The reports come a day after the Mosul consulate said ISIL fighters seized 28 Turkish truck drivers.
The ISIL jihadist group claimed effective control of Mosul and much of the northern Nineveh Province on June 10 after days of heavy fighting.
The latest reports now say ISIL militants have taken control of most of the central Iraqi city of Tikrit, the capital of Salah al-Din Province, which lies roughly halfway between Baghdad and Mosul.
The International Organization for Migration (IOM) estimated that 500,000 people had left the city after its seizure by the militants.
The IOM said the violence in Mosul "has resulted in a high number of casualties among civilians."
Iraqi Foreign Minister Hoshyar Zebari, meanwhile, said Baghdad will cooperate with Kurdish "peshmerga" forces in the north to try to drive militants out of Mosul, which he called a "serious, mortal threat."
Zebari, who was speaking during a trip to Greece, did not give details about cooperation between the two forces. But he said, "There has to be a quick response to what has happened."
The peshmerga are the semiautonomous Kurdish region's own large and disciplined military force.
The Kurdish region consists of four provinces -- Irbil, Duhok, Sulaymaniyah, and Halabjah -- and has its own regional government.
Meanwhile, Reuters quoted security sources as saying ISIL militants advanced into the oil-refinery town of Baiji on June 11, setting the courthouse and police station on fire.
ISIL fighters have been holding parts of Ramadi, the capital of western Anbar Province, and much of the nearby city of Fallujah since early January.
Iraqi Prime Minister Nuri al-Maliki has asked parliament to declare a state of emergency.
Map of territories in Iraq occupied by ISIS as of June 10
Parliament is now set to debate the request on June 12.
Parliament speaker Osama al-Nujaifi, a Sunni from Mosul, called the rout "a disaster by any standard."
The United States and United Nations have expressed concern after the ISIL took control of most of Iraq's second-largest city.
U.S. State Department spokeswoman Jen Psaki said the ISIL militants posed a threat to the entire region.
She said Washington backed "a strong, coordinated response to push back against this aggression."
UN Secretary-General Ban Ki-moon urged Iraqi political leaders "to show national unity against the threat facing Iraq."
The prime minister of Iraq's Kurdish region, Nechrvan Barzani, has sharply criticized Baghdad's handling of the Mosul crisis, saying the Kurds had tried unsuccessfully to work with Iraqi security forces to defend the city.
In a statement, Barzani urged Kurds to aid those displaced from Mosul and called on the UN refugee agency to help with the relief effort.
With reporting by AFP, Reuters, and dpa