Three assailants opened fire after entering a Turkish restaurant in Erbil, capital of the Kurdish region in Iraq.

A Turkish diplomat was killed after gunmen entered an upscale restaurant where he was dining and opened fire in Erbil, capital of the Kurdish autonomous region in Iraq.

Intelligence sources told Al Jazeera another individual was killed in Wednesday’s shooting, while one person was wounded.

The attackers escaped the HuQ Qabaz restaurant through the back door and security forces were searching for them.

Turkish Foreign Minister Mevlut Cavusoglu said the attack on the restaurant was carried out by three people. The assailants also fired at Iraqi nationals sitting at a table next to Turkish consulate employees, killing one and seriously wounding another, the minister said.

“We are continuing our contacts so that details concerning the issue of the apprehension of the assailants, and what is behind the attack, are brought to light,” Cavusoglu said.

No immediate claim of responsibility was made for the shooting. Such assaults are rare in Erbil.

The restaurant owner told Turkey’s state-run Anadolu news agency the killings were carried out by an individual in plain clothes and carrying two guns.

Security forces sealed off the area keeping journalists on the other side of the road. The front window facade of the restaurant was shattered.

‘N ecessary response’

Turkish President Recep Tayyip Erdogan was quick to condemn what he said was an “atrocious attack against our consulate employees in Erbil”.

“We are continuing our efforts with the Iraqi authorities and local authorities to ensure that the perpetrators of the attack are found quickly,” Erdogan said in a post on Twitter.

Ibrahim Kalin, Erdogan’s spokesman, vowed Turkey would deliver “the necessary response … to those who committed this treacherous attack”.

A manhunt for those responsible was on, but Kalin did not speculate who might be responsible for the shooting.

In recent weeks, Turkey has been carrying out cross-border military operations against the outlawed Kurdistan Workers’ Party (PKK) in the Hakurk region of northern Iraq.

The PKK has fought against the Turkish state in predominantly Kurdish southeastern Turkey since the 1980s, and more than 40,000 people have been killed in the conflict.

It is designated a “terrorist” group by Ankara, the European Union, and the United States.

Direct retaliation?

Asked whether the attack could be the work of the PKK, Cavusoglu said it was not yet clear if the shooting was done by the group, saying Iraqis at the restaurant were also targeted.

In a statement issued on Saturday, the foreign ministry announced the start of “Operation Claw-2” aiming to destroy caves and shelters used by PKK members. It said the operation began late Friday with commandos, air raids and artillery.

On Wednesday, Turkey launched air raids that killed at least seven members of the PKK.

Ege Seckin, an analyst with HIS Markit, suggested Wednesday’s shooting was in response to Turkish military operations in the area, including the killing of a high-profile PKK figure in an air attack last week.

“This is likely to have been direct retaliation to that, and also a warning to the Kurdish authorities, the KRG, about their cooperation with Turkish forces. The KRG will see the attack as an infringement of its sovereignty and it will deepen that divide between the two sides,” Seckin told Al Jazeera.