A Turkish diplomat was among two people shot dead on Wednesday in Irbil, the capital of Iraq’s Kurdistan Region.
The victims, who were eating at a restaurant when gunmen opened fire, were reportedly Turkey’s deputy consul in the city and an Iraqi civilian.
Turkish President Recep Tayyip Erdogan condemned the “heinous attack”.
No-one has so far said they were behind it. The Kurdistan Workers’ Party (PKK), which has fought Turkey for decades and has bases in Iraq, has denied any role.
The shooting took place at about 14:30 (11:30 GMT) on Wednesday at HuQQabaz restaurant on Airport Road, between Irbil’s Dream City and Empire districts.
Turkish Foreign Minister Mevlut Cavusoglu said three assailants opened fire at the restaurant, killing the Turkish diplomat and the Iraqi civilian while injuring another Iraqi.
The diplomat and the Iraqis were sitting at adjacent tables.
The Kurdistan Region’s internal security forces, the Asayish, said it had launched a full investigation and had contacted Turkish diplomats to offer them assistance.
A spokesman for President Erdogan, Ibrahim Kalin, wrote on Twitter: “The necessary response will be given to those who staged this treacherous attack.”
The Kurdistan Regional Government said it strongly condemned the killing and vowed to find the perpetrators and hold them accountable.
An Iraqi foreign ministry spokesman said it would closely follow the investigation.