Two attackers killed five people and wounded 22 others on Wednesday in an attack at the headquarters of Turkish Aerospace Industries (TUSAS) in the Turkish capital of Ankara.
Interior Minister Ali Yerlikaya said both attackers were killed after the attack, adding two of the injured are in critical condition. TV broadcasters showed footage of armed assailants entering the TUSAS building near Ankara.
"Two terrorists were neutralised in the terror attack on the TUSAS Ankara Kahramankazan site," Mr Yerlikaya said.
"Sadly, we have five martyrs and 22 wounded in the attack. Three of the injured were already discharged from hospital, 19 of them under treatment," he said.
Turkish President Tayyip Erdogan, alongside Russia's Vladimir Putin at a BRICS conference in the Russian city of Kazan, condemned the attack.
TV broadcasters earlier showed footage of armed attackers entering the TUSAS building, with footage of gunfire in a parking lot and the two attackers carrying assault rifles and backpacks as they entered the building.
It was not immediately clear who was behind the attack. No group had claimed responsibility.
Prosecutors have launched an investigation, state-run Anadolu Agency reported.
TUSAS is one of Türkiye's most important defence and aviation companies. It produces KAAN, the country's first national combat aircraft, among other projects.
Private NTV television reported a group of attackers arrived at an entry of the company headquarters inside a taxi during a changing of the security personnel.
Local media reported a loud explosion at the site and showed footage of an exchange of gunfire.
At least one of the attackers detonated a bomb, NTV said, while other attackers managed to enter the complex.
Emergency services were dispatched to the site, Anadolu Agency reported.
Some media reports claimed a suicide attack had occurred and that there were hostages inside the building, though officials have not confirmed this.
Witnesses told Reuters that employees inside the building were taken by authorities to shelters and no one was permitted to leave.
They said bombings may have taken place at different exits as employees were leaving work for the day.
NATO head Mark Rutte said the military alliance would stand with its ally Türkiye amid news of the attack.
"Deeply concerning reports of dead and wounded in Ankara. #NATO stands with our Ally #Turkey. We strongly condemn terrorism in all its forms and are monitoring developments closely," Mr Rutte said in a post on X.
Russian President Vladimir Putin, who was meeting with Mr Erdogan at the BRICS summit, offered him condolences over the attack.
The European Union delegation in Türkiye also condemned the attack.
Reuters/AP