From their website:
Two Amnesty International representatives have been detained by police in Cairo after the Hisham Mubarak Law Centre was taken over by military police this morning.
The Amnesty International staff members were taken, along with Ahmed Seif Al Islam, Khaled Ali, a delegate from Human Rights Watch and others, to an unknown location in Cairo. Amnesty International does not know their current whereabouts.
View Link [amnesty.org]