Two attackers killed five people and wounded 22 others on Wednesday in what Ankara called a terrorist attack at the Turkish Aerospace Industries headquarters, where witnesses said they heard gunfire and an explosion.

A series of explosions and gunshots were heard at TUSAS, Turkey’s state-run aerospace and defense company, in an attack Turkey’s defense chief blamed on the outlawed Kurdistan Workers Party.

An attack at Turkish Aerospace Industries' headquarters near Ankara resulted in four deaths and 14 injuries. Two attackers were killed, and authorities termed it a terrorist act. Investigations are ongoing as no group has claimed responsibility.

No group immediately claimed responsibility. Turkey’s interior minister said it was “most likely carried out” by the Kurdistan Workers’ Party, or PKK.

Footage broadcast on Turkish television and shared on social media Oct. 23 showed an attack on an aerospace company's headquarters near the capital, Ankara.

Attackers armed with explosives and rifles assaulted the headquarters of a Turkish state-run aerospace company on Wednesday.