Hours before the consulate attack, an overnight bomb attack at a police station in Istanbul injured three policemen and seven civilians and caused a fire that collapsed part of the three-story building. Police said the assailants exploded a car bomb near the station. Unknown assailants later fired on police inspecting the scene of the explosion, sparking another gunfight with police and leaving a member of the police inspection team and two assailants dead.
There were no immediate claims of responsibility, and it was not known if the attack on the police station was connected to the consulate assault.
Also Monday, rebels from a Kurdish group in the southeastern province of Sirnak fired at a helicopter carrying conscripts who had finished their term of duty or were taking leave, killing one of them and injuring another, the military said. Four police were also killed in Sirnak province when their armored vehicle struck a roadside bomb, the Dogan news agency reported. The Kurdish group and the DHKP-C have Marxist origins and cooperated in the past.
Turkey has been in a heightened state of alert since starting what officials termed a synchronized "war on terrorism" last month, including airstrikes against fighters from the Islamic State in Iraq and the Levant (ISIL) in Syria and the Kurdistan Workers Party (PKK) in northern Iraq.
On Sunday the U.S. military announced that a detachment of six F-16 fighter jets and about 300 personnel arrived at Turkey's southern Incirlik air base to join the fight against ISIL.
Turkey last month carried out a major security sweep, detaining some 1,300 people suspected of links to organizations such as the PKK, ISIL and the DHKP-C.
The U.S. Embassy said U.S. officials were working with Turkish authorities to investigate the consulate attack. The consulate will remain closed to the public until further notice, it added.