Islamic State Jammu and Kashmir (ISJK) chief, and most wanted militant commander Zakir Musa has been killed in an encounter with security forces in Tral area of South Kashmir's Pulwama district of Thursday evening.

Sources said on a credible input about the presence of Musa in Dadsra area of Tral, 30 kilometres from capital Srinagar, a Cordon and Search Operation (CASO) was launched by the army's 42 Rashtriya Rifles (RR) and Special Operations Group (SOG) of the Jammu and Kashmir Police.

A police officer said that the search party tried to persuade ISJK chief to surrender, but he fired at them leading to an encounter. In the retaliatory action, Musa was slain.

The security forces later officially confirm his killing.

Authorities ordered the closure of all educational institutions in the valley on Friday, fearing possible law and order problem. The authorities have also snapped internet services across the valley to prevent 'rumour mongering'.

Musa, who joined militancy after leaving his B Tech course in Chandigarh in 2013, prophessed an ideology similar to that of the Islamic State (IS) -- to establish Shariat (Islamic law) in the restive Himalayan state.

He was a close associate of 21-year old Burhan Wani, new face of Kashmir's militancy, who was killed in an encounter with security forces on July 8, 2016.

Musa, who was said to be active in the upper reaches of Tral, quit indigenous Hizbul Mujahideen (HM) in 2017 after he called separatist leaders "hypocrite, infidels, and followers of evil."