At least four people have been killed and 14 others wounded in an attack on the headquarters of Turkey’s aerospace and defence company Turkish Aerospace Industries (TUSAS) near the capital Ankara, Turkey’s president has said.

President Recep Tayyip Erdogan, who was holding talks in Russia with Vladimir Putin at the time of the attack on Wednesday, confirmed the toll, and condemned what he said was a “heinous terrorist attack”.

“Two terrorists were neutralised” in the incident at the headquarters of the state-run firm, Turkish Interior Minister Ali Yerlikaya wrote on X.

Footage from the scene broadcast by local media showed huge clouds of smoke and a large fire raging at the site in Kahramankazan, a small town some 40 kilometres (25 miles) north of Ankara.

According to local media reports, there was a loud explosion at the site and subsequent gunfire.

Security camera images from the attack, aired by broadcasters, showed a man in plainclothes carrying a backpack and holding an assault rifle.

The images also appeared to show that at least one woman, carrying an assault rifle, was among the assailants.

There was no immediate claim of responsibility for the attack.

Emergency services were dispatched to the site, state-owned Anadolu Agency reported.

“Deeply concerning reports of dead and wounded in Ankara,” said NATO head Mark Rutte in a post on X.

“NATO stands with our ally Turkey. We strongly condemn terrorism in all its forms and are monitoring developments closely,” he added.

TUSAS is one of Turkey’s most important defence and aviation companies. It produces KAAN, the country’s first national combat aircraft, among other projects.

The attack occurred as a major trade fair for the defence and aerospace industries was taking place in Istanbul, which was visited this week by Ukraine’s top diplomat.

Turkey’s defence sector, which is widely known for its Bayraktar drones, accounts for nearly 80 percent of the nation’s export revenues with revenues expected to top $10.2bn in 2023.