Four people have been killed in an apparent terror attack in Turkey at the headquarters of a defence and aerospace company, the country’s president has said.
Multiple gunshots were heard after Turkish security forces entered the site, in the capital city of Ankara, local media reported.
“We have four martyrs. We have 14 wounded,” President Recep Tayyip Erdogan said during a meeting with Russian President Vladimir Putin on the sidelines of a meeting in Kazan, Russia.
Turkey attack latest: Follow live updates
He added: “I condemn this heinous terrorist attack and wish mercy on our martyrs.”
Mr Putin, who is hosting world leaders at a summit of the Brics bloc of developing economies, expressed his condolences.
Interior minister Ali Yerlikaya said at least two of the attackers had been killed. It is unclear whether there were more people involved.
Mr Yerlikaya said three of the injured are in a critical condition.
CCTV images from the attack appeared to show a man in plain clothes carrying a backpack and holding an assault rifle.
Selim Cirpanoglum, mayor of the district of Kahramankazan, told The Associated Press that the attack had abated but could not provide more details.
TUSAS (Turkish Aerospace Industries) is one of Turkey’s most important defence and aerospace companies and produces KAAN, the country’s first national combat aircraft, among other projects.
It was not immediately clear who was behind the attack.
Kurdish militants, the Islamic State group and leftist extremists have all carried out attacks in the country in the past.
Videos circulating on social media show residents ducking for cover as large explosions were heard, followed by what seemed to be gunfire.
One video, filmed from a car park, shows people looking on as dust filled the air a short distance away as more gunfire was heard.
A group of assailants were said to have arrived at an entrance to the complex in a taxi, during a change of security, according to NTV television.
At least one attacker reportedly detonated a bomb while others were said to have entered the complex.
At least one woman, also carrying an assault rifle, was among the assailants, according to images aired on television.
NTV added that gunfire at the site was continuing and some personnel at the complex may have been taken hostage.
Security forces, ambulances and firefighters were all said to have been dispatched to the site.
Employees were taken to a safe area, HaberTurk television said.
NATO general secretary Mark Rutte said: “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.”
TUSAS designs, manufactures and assembles civilian and military aircraft, unmanned aerial vehicles and other defence industry and space systems.