Two militant outfits - al Mansoorian and Islamic Jehad Front - separately claimed responsibility for the killing of Jammu and Kashmir Minister of State for Education Ghulam Nabi Lone at his official residence in the high-security Tusli Bagh area.
The attack, which took place at around 0900 hrs on Tuesday, comes a day after a Communist Party of India-Marxist leader, Ghulam Nabi Ganai, was killed in Matan, 65 kms from Srinagar.
A caller claiming to be the spokesman of al-Mansoorian told BBC that its activists were behind the attack in the high security area of Srinagar.
A spokesman of Islamic Jehad Front called the CNS news agency and claimed the attack was carried out by its members.
Two security personnel and a militant were also killed and a civilian injured in the attack. Militants, firing indiscriminately and lobbing grenades, entered the house of CPI(M) member of legislative Assembly, Mohammad Yousuf Tarigami and after being challenged by security personnel there, barged into the neighbouring house of Lone and fatally injured him.
Lone was rushed to the hospital, where he was declared brought dead.