While Malik was taken into custody from here and shifted to Central Jail till September 11, Mirwaiz was placed under house arrest to prevent the separatist leaders from going to Delhi on Friday.
Hurriyat chief Syed Ali Shah Geelani is under house arrest for the past several years now.
Malik, Geelani and Mirwaiz on Wednesday announced that they will hold a dharna outside the NIA office in Delhi and court arrest against the alleged harassment by the NIA.
The NIA has recently been conducting raids and arresting people associated with the separatist leaders in connection with alleged money laundering and some other cases.