Turkey's foreign ministry said in a statement today that jihadist group the Islamic State of Iraq and the Levant (ISIL) had kidnapped 49 of its citizens at the Mosul consulate and taken them to another part of the city.
"All those involved should know that if our citizens are harmed in any way, they will be the subject of harsh reprisals," Turkish media quoted Foreign Minister Ahmet Davutoglu as saying at the United Nations in New York.
Turkish officials told AFP earlier that militants storming the consulate had kidnapped 48 Turks, including the consul, staff members, guards and three children.
Prime Minister Recep Tayyip Erdogan held an emergency meeting with President Abdullah Gul, spy chief Hakan Fidan and the Turkish armed forces chief of staff Necdet Ozel to discuss security measures and how to secure the release of the hostages.
Ankara also informed its NATO allies of the situation but stopped short from requesting any help, said a source after the meeting in Brussels.
The kidnappings come amid growing concern in Ankara over the rise of radical Islamist groups across the border in Syria.
Ankara also vowed to protect its territory against any attacks after militant Islamists threatened a historic shrine under Turkish jurisdiction in the northern city of Aleppo.
Davutoglu said his ministry had sent order to evacuate the consulate two days ago but were informed that it was more dangerous for the staff to leave because of security concerns.
"Right now, our priority is to bring our citizens back to the country alive, which is more important than unveiling an initiative of some kind," Davutoglu was quoted as saying without elaborating.
Turkey, which backs the uprising against President Bashar al-Assad, has repeatedly denied claims that it is providing shelter or backing Al-Qaeda linked groups in Syria.