ISTANBUL: Turkey raised the alert level to orange at all airports on Thursday after a terrorist attack in Ankara the previous day that left five dead and 22 injured, according to local media.

The Directorate General of Civil Aviation issued a directive implementing heightened security measures across all airports in response to potential terrorist threats, Xinhua news agency reported quoting the Turkish broadcaster NTV.

Following this decision, security measures have been intensified at Istanbul's two international airports, Sabiha Gokcen and Istanbul Airport.

Both airports have advised passengers on their websites to arrive at least three hours before departure to avoid delays due to the heightened security.

Interior Minister Ali Yerlikaya announced on Wednesday that the deadly attack at the Turkish aerospace and defence company TUSAS was likely carried out by the outlawed Kurdistan Workers' Party (PKK). He confirmed that both attackers, a man and a woman, had been killed.

Türkiye has three alarm levels in aviation: yellow, orange, and red, to enhance security measures. The yellow level signals an elevated risk due to potential threats, prompting heightened security measures without drastic changes. The red level signifies a severe risk with an imminent threat, triggering emergency protocols such as evacuations, lockdowns, and extensive security measures.