A prominent Turkish diplomat was among two people gunned down in a popular Iraqi restaurant in “a treacherous attack” that has officials in Turkey vowing to retaliate, the BBC reported Wednesday.

The victim, who is not identified in the report but is thought to be Turkey’s deputy consul general in Irbil, was among two people killed when gunmen opened fire on a lunchtime crowd at HuQQabaz restaurant, a popular eatery in the city’s Empire City neighborhood.

No one has claimed responsibility for the attack, but Turkish Kurdish militants are known to be based near the northern Iraqi city, prompting a stern response from Turkey.

In a statement on Twitter, Turkish presidential spokesperson Ibrahim Kalin said a “necessary response will be given to those who committed this treacherous attack.”

Turkish Foreign Minister Mevlut Cavusoglu said the second victim was a civilian.

Authorities are seeking the gunmen in the shooting.