Istanbul: Two attackers opened fire on the US consulate building in Turkey’s biggest city, Istanbul, on Monday and fled when police shot back, broadcaster CNN Turk said.

The Cihan news agency said those involved in the attack on the building in Istanbul’s Sariyer district included one man and one woman. Reuters could not immediately confirm the reports.

CNN Turk said there were no casualties.

Turkey has been in a heightened state of alert since it launched what officials described as a ‘synchronised war on terror’ last month, including air strikes against Islamic State fighters in Syria and Kurdish militants in northern Iraq, and the detention of hundreds of suspects at home.

US diplomatic missions have been targeted in Turkey in the past.

The far-leftist Revolutionary People’s Liberation Army-Front (DHKP-C), whose members are among those detained in recent weeks, claimed responsibility for a suicide bombing at the US embassy in Ankara in 2013 which killed a Turkish security guard.