ANKARA

The PKK terrorist organization planned last week's deadly Ankara blast, while the YPG, which is the military wing of Syrian terror group PYD, provided assailants for the attack, official security sources told Anadolu Agency Monday.

Speaking on condition of anonymity, Turkish officials said the attack was carried out jointly by the PKK and the YPG, both of which are seen as terrorist organizations by Turkey.

Turkish President Recep Tayyip Erdogan also said earlier this week that the attack was carried out by a YPG member.

A total of 28 people were killed and 81 others injured Wednesday when a bomb hit military-owned vehicles in the Turkish capital of Ankara on Feb. 17.

According to security officials, the vehicle used in the attack was hired by a car theft ring from a rental company based in western Turkey's Izmir province.

They added that the vehicle was also taken to Istanbul and southeastern Diyarbakir provinces before the attack, while explosives were strapped to the car in Ankara.

According to the Turkish government, Syrian national Salih Necar was the suicide attacker involved in the blast; the bomber worked as a construction worker in Ankara and stayed with two members of the terrorist organization before the attack, officials added.

Turkey has held 21 suspects so far across the country in connection with the attack.