ANKARA, Turkey (AP) — Assailants set off an explosive and opened fire in an attack Wednesday on the premises of the Turkish state-run aerospace and defense company TUSAS, killing three people and wounding several, officials said.

At least two of the attackers died, Interior Minister Ali Yerlikaya said. He said 14 people were wounded.

Selim Cirpanoglum, mayor of the district of Kahramankazan, told The Associated Press that the attack on the company in the outskirts of the capital, Ankara, had abated but could not provide more details.

It was not clear who may be behind the attack. Kurdish militants, the Islamic State group and leftist extremists have carried out attacks in the country in the past.

Private NTV television said a group assailants arrived at an entry to the complex inside a taxi during a changing of the security personnel. At least one of the assailants detonated a bomb, while other attackers managed to enter the complex.

Helicopters were seen flying above the premises in Ankara’s Kahramankazan district, the station reported.

TUSAS designs, manufactures and assembles both civilian and military aircrafts, unmanned aerial vehicles and other defense industry and space systems.

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

At least one woman, also carrying an assault rifle, was among the assailants, according to the images.

Earlier, media reports said an explosion followed by gunfire was heard at the complex and employees were taken to a safe area.