"Curfew has been imposed in areas falling under the jurisdiction of Nowhatta and M.R.Gunj police stations in Srinagar city along with Baramulla," a senior police official said.
Authorities had lifted curfew from the entire Valley on Wednesday after 53 days since the unrest started on July 9.
One youth identified as Danish Ahmad, 18, was killed in firing by the security when a mob pelted stones at a passing army convoy in Rafiabad area of Baramulla district on Wednesday.
Mobs also torched the house of ruling Peoples Democratic Party (PDP) Rajya Sabha member, Nazir Ahmad Laway in Chawalgam village in Kulgam district.
Reports here said the mob first torched the guard room at his house and then set fire to the main building.
A stone pelting mob engaged security forces in clashes in Sopore town on Thursday morning while another mob torched a three-wheeler in Nawa Kadal area of Srinagar city for defying the shutdown called by the separatists.
The separatists have issued a fresh protest calendar through which they have asked people to continue the shutdown till September 8.
For the last 55 days, life has remained totally paralysed in the Valley due to curfew and protest shutdown called by the separatists.
Educational institutions have remained closed for the last 55 days as shops, markets and public transport have also remained suspended.
A total of 72 people -- 69 civilians and three policemen have killed and over 11,000 others injured in the Valley during this period.