Amnesty International says Egypt's military rulers have acknowledged carrying out so-called 'virginity tests' on female protesters — the first time the army has admitted to the much criticized practice.

Amnesty said in a report published Monday that Maj. Gen. Abdel Fattah al-Sisi, a member of the military council ruling Egypt, justified the tests as a way to protect the army from rape allegations.

But the rights watchdog said al-Sisi vowed the military would not conduct such tests in the future.

The 'virginity test' allegations first surfaced after a March 9 rally in Cairo's Tahrir Square that turned violent when men in plainclothes attacked protesters and the army intervened forcefully to clear the square.

Amnesty has found 18 female detainees were forced to the tests.