At least three people have been killed and 14 injured in an attack at the headquarters of an aviation company near the Turkish capital Ankara, authorities have confirmed.
The country's Interior Minister Ali Yerlikaya posted on X that two attackers were "neutralised" in the incident, which saw gunshots and explosions.
Initial images shown by the NTV television channel were of a large cloud of smoke in front of the entrance of Turkish Aerospace Industries (TAI), which is located some 40km (25 miles) outside the capital.
Firefighters and medical teams have been dispatched to the scene.
It is not clear how many people were involved in the attack and if there are other suspects to be apprehended.
Local media is reporting that blast took place around the time of a shift change, and staff had to be directed to shelters.
Some outlets have carried a photograph purporting to show one suspect climbing over a turnstile and entering the building holding a gun.
Ankara metropolitan mayor Mansur Yavas said in a statement earlier on Wednesday that he was “deeply saddened” by the news.
“I wish God's mercy upon our martyrs and a speedy recovery to our wounded. We condemn terrorism. My condolences."
Turkey’s Justice Minister, Yilmaz Tunc, announced on X that the Ankara Chief Public Prosecutor’s Office has launched a “judicial investigation” into the incident.
Turkey’s President, Recep Tayyip Erdogan, is currently in the Russian city of Kazan for the Brics summit of major emerging market nations, including Brazil, Russia, India, China and South Africa.
TAI is a key player in Turkey’s aerospace industry, designing, developing and manufacturing various aircraft for commercial and military use.
It is the company designated by the Nato member to be the licensed manufacturer for the US-designed F-16 fighter jets. Tai also plays a role in modernising older aircraft for use by the Turkish military.
The firm's two principle owners are the Turkish Armed Forces and a civilian arm of the Turkey's government charged with improving its defence capabilities and manage military procurement.
The blast took place as a major trade fair for defence and aerospace industries was going on in Istanbul this week.