Senior Hurriyat (M) leader and PPP chairman Hilal Ahmad War was detained from his residence in Srinagar on Thursday.
A spokesman said a police party raided his residence in Maisuma area of the city and detained him.
His arrest has come as the Joint Resistance Leadership comprising Syed Ali Geelani, Mirwaiz Umar Farooq and Yasin Malik has urged people to observe human rights week from December 3 to highlight rights violations.