Separatist leader and Jammu and Kashmir Liberation Front (JKLF) chief Muhammad Yasin Malik was arrested by Jammu and Kashmir police in Srinagar on Monday ahead of a meeting called by the Hurriyat Conference.
Police personnel were posted outside hardline Hurriyat Conference chairman Syed Ali Shah Geelani's residence at Hyderpora where the separatists leaders were to hold a meeting and later address a press conference, police said.
No one was allowed to enter Geelani's residence.
Authorities also placed Hurriyat co-chairman Mirwaiz Umar Farooq under house arrest on Monday to prevent him from attending the meeting.
Malik, who was only last week released from jail, had warned of "dire consequences" and street protests in response to the NIA raids conducted at the residences of separatist leaders.
In a joint statement with Geelani and Farooq, the JKLF chief had slammed the raids as an attempt to discredit the top brass of the separatist camp and their movement to liberate Kashmir.
"We warn Delhi of dire consequences if all these harassing measures are not stopped forthwith. If these unnecessary raids are not stopped, people will take to streets and resent these arbitrary measures with their full might and will," they had said on Saturday.
The NIA conducted the raids at 23 locations in Kashmir, Haryana and Delhi in connection with a case of alleged funding received by separatist groups for carrying out subversive activities in the Kashmir Valley.