Moulvi Mushtaq Ahmad, All Parties Hurriyat Conference leader Mirwaiz Omar Farooq's uncle, on Monday died of injuries sustained in a militant attack.
Doctors treating Ahmad, a senior leader of the Mirwaiz's Awami Action Committee, declared him dead in the evening, according to official sources in Srinagar.
Militants had shot Ahmad while he was praying in a mosque last week.
The Save Kashmir Movement had admitted responsibility for the attack.
He was immediately taken to SMHS Hospital in Srinagar, but on doctors' advice he was shifted to the Soura Medical Institute.
His condition deteriorated three days back and the Centre rushed a team of specialists to Srinagar, who examined Ahmad on Saturday.
However, despite their best efforts the doctors couldn't save him.
Downtown Srinagar, the AAC's stronghold, was tense after the news became public.
Angry youths pelted stones on vehicles and forced shopkeepers to pull down their shutters.
Irate mourners also gheraoed the SMI doctors, including the director of the institute.
The protestors alleged that the doctors had deliberately delayed the announcement of his death.
The mourners were waiting for the Mirwaiz to arrive at the hospital, from where the body will be taken for burial on Tuesday.