Four people have been killed and 14 wounded in an attack on an aerospace firm near the Turkish capital of Ankara, the government said.

Two attackers were killed in the attack after witnesses heard gunfire and an explosion at the site, interior minister Ali Yerlikaya said.

Broadcasters showed images of a damaged gate and footage of an exchange of gunfire in a car park, as well as attackers carrying assault rifles and backpacks as they entered the building

"Two terrorists were neutralised in the terror attack on the Tusas Ankara Kahramankazan site. Sadly, we have three martyrs and 14 wounded in the attack," Mr Yerlikaya said.

The cause of the blast and the identity of the attackers remain unclear. No group had claimed responsibility. Prosecutors have launched an investigation, state-run Anadolu Agency reported.

Tusas is Turkey's largest aerospace manufacturer, currently producing a training craft, combat and civilian helicopters, as well as developing the country's first fighter jet, Kaan.

The firm is owned by the Turkish Armed Forces Foundation and government and employs more than 10,000 people.