The hardline Hurriyat group, headed by Syed Ali Geelani, has called for a march to Khanqah-i-Moula mosque area in the Old city and post Friday prayer protests across the Valley.
"In order to prevent damage to civilian life and property, restrictions have been imposed in Old City areas in Srinagar," a police officer said here.
The protests are part of the group's 'Quit Kashmir' programme to highlight alleged human rights violations.
Geelani, who had been lodged in a hut in the high-security Chashma Shahi area after he was arrested last month under the Public Safety Act (PSA), was shifted to the Sher-e-Kashmir Institute of Medical Sciences (SKIMS) here Thursday for treatment.
The ruling National Conference, in its working committee resolution here Thursday, urged the state government to release all political leaders.
Reports reaching here from north Kashmir's Sopore, Handwara and Bandipora towns said curfew had been imposed while restrictions were being strictly enforced in Baramulla town.
In south Kashmir too restrictions were imposed to thwart the proposed separatist protests.
Shops, educational institutions, banks and other business establishments remained closed in areas under restrictions in the valley while public transport went off roads.
The valley has been virtually paralysed due to violent protests against civilians being killed in firing by security forces. Fourteen people, including a 25-year old woman, have been killed in firing by security personnel across the Kashmir Valley since June 11.
The army was called in to help maintain law and order as the violence spiralled.
The state government has decided to conduct an independent enquiry into all the civilian deaths.