Four people were killed and 14 others wounded in an attack on the headquarters of a top Turkish defence firm near Ankara, Turkish officials said Wednesday.
President Recep Tayyip Erdogan, who was holding talks in Russia with Vladimir Putin at the time, confirmed the toll, and condemned what he said was a "heinous terrorist attack" at state-run Turkish Aerospace Industries (TAI).
Interior Minister Ali Yerlikaya said three of the injured were in critical condition and that two attackers "a woman and a man, have been neutralised".
He said work was under way to determine their identities but did not say whether there were any other attackers still at large.
Local media broadcast footage showing clouds of smoke and a large fire raging at the site in Kahramankazan, a small town some 40 kilometres (25 miles) north of Ankara.
The incident happened as Erdogan was meeting Vladimir Putin at a summit in Kazan, with the Russian leader expressing his condolences over the attack.
Media outlets which had been showing live footage from the scene were forced to halt their broadcasts after Turkey's media watchdog ordered a blackout of images from the site.
Haberturk TV said there was an ongoing "hostage situation" without giving further details, while the private NTV television spoke of gunshots after the blast, which took place around 4:00 pm (1300 GMT).
There was no immediate claim for the attack but the justice minister said an investigation had been opened.
NTV spoke of a suicide attack, saying "a group of terrorists" had burst into TAI's headquarters and one of them blew themself up.
Images shown by Haberturk suggested one attacker was a woman, while Sabah newspaper published a CCTV image from cameras at the building's entrance of a black-clad young man with a moustache carrying a rucksack and what appeared to be an assault rifle.
The attack drew condemnation from Transport Minister Abdulkadir Uraloglu as well as opposition leader Ozgur Ozel, who heads the CHP.
"I condemn the terrorist attack against TAI facilities in Kahramankazan... I condemn terrorism, no matter who or where it comes from," Ozel wrote on X.
According to TAI's website, the state-run company, which is also a major arms producer, employs 15,500 people and has a vast production site covering an area of five million square metres.
The blast occurred as Erdogan was with Putin in the Russian city of Kazan for the BRICS summit of major emerging market nations, including Brazil, Russia, India, China and South Africa.
"I would like to express my condolences in connection with the terror attack," Putin told him at the start of their meeting.
NATO chief Mark Rutte also offered the alliance's backing to member state Turkey in a call with Erdogan following the attack.
"I just spoke with (President) Erdogan about the terror attack in Ankara. My message was clear: NATO stands with Turkiye," Rutte wrote on X, using the country's official Turkish name.
The Turkish city of Istanbul is currently hosting a major trade fair for the defence and aerospace industries at the moment, visited this week by Ukraine's top diplomat.
Turkey's defence sector, which is known for its Bayraktar drones, accounts for some 80 percent of the nation's export revenues.
Contracts worth $10.2 billion were signed last year, according to Haluk Gorgun, head of Turkey's state Defence Industry Agency (SSB).
In the first eight months of this year, defence export revenues reached $3.7 billion, up nearly 10 percent from same period a year earlier, Gorgun said.
The last attack in Turkey took place in January when a man was shot dead by two gunmen who opened fire inside a Catholic church in Istanbul.
That attack was claimed by Islamic State (IS) group jihadists.
In October 2023, two policemen were injured in an attack in the government district in Ankara.
Police shot dead one assailant while the other died in an apparent suicide blast outside the interior ministry.
That attack was claimed by the PKK (Kurdistan Workers' Party) which has waged an insurgency against the Turkish state since 1984 in a conflict that has claimed tens of thousands of lives.
