He suggested that it might be equally permeable to anyone fleeing Afghanistan.
They said most had fled Afghanistan in recent weeks.
The two sisters moved into a cheap guesthouse as they prepared to flee Afghanistan.
Their ranks are thought to be 650 strong, including fighters who fled Afghanistan.
Ghafour and her parents fled Afghanistan in 1981 when she was four years old.
There is no evidence that he has yet tried to flee Afghanistan.
Other refugees fleeing Afghanistan have said that the going rate is $200 a family.
More than six million people, almost half the nation, fled Afghanistan during the war, and by 1997 some 2.7 million were still in exile.
But Mohammed eventually decided he wanted a life free of war and fled Afghanistan.
He also worked at the university prior to fleeing Afghanistan in 1988.