Hurriyat Conference chairman Syed Ali Shah Geelani was arrested on 25 July by the Jammu and Kashmir police for defying the terms of house arrest.
He was arrested in Srinagar while trying to lead a protest march to Anantnag.
Geelani was taken to the Humhama Police Station after being detained outside his residence at New Airport Road here.
Separatist leader Mirwaiz Umar Farooq was also detained by police.
The Hurriyat leader had asked people to move towards South Kashmir's Anantnag district and participate in a rally to be held at Lal Chowk there after the Zuhar (afternoon) prayers.
The authorities on Monday imposed curfew in four south Kashmir districts to prevent a separatists-called protest march.
The police said strict curfew will remain in Anantnag, Kulgam, Shopian, and Pulwama districts while restrictions will continue in parts of Srinagar, Kupwara, Sopore, and Baramulla.
According to reports, all senior separatist leaders, including Syed Ali Geelani, Mirwaiz Umer Farooq, Yasin Malik and Shabir Shah, have been either placed under house arrest or taken into preventive custody by the authorities ever since the ongoing unrest started in the Valley on 9 July.
The separatists have extended their protest shutdown call till 29 July.
Meanwhile, another injured youth Sameer Ahmad Wani succumbed to his injuries last evening, thereby taking the death toll to 49.
-With ANI inputs