ISTANBUL - A bomb threat Monday forced Turkish Airlines to cancel a domestic flight, according to press reports.

Crew members found a threatening note posted on the restroom door claiming a bomb was aboard the plane before it took off from Istanbul's Ataturk airport towards Turkey's Anatolian province of Kayseri, private Dogan news agency reported.

It said security forces promptly evacuated the plane and conducted a search but found nothing suspicious on the plane.

However, Istanbul and other Turkish cities, still recovering from a series of bomb attacks in recent months, are bracing themselves for more to come.