Zahid Rasool Bhat, who was being treated for burn injuries in Delhi's Safdarjung Hospital, died on Sunday, a senior police officer told IANS here.
Bhat and another Kashmiri from Anantnag district, Showkat Ahmad Dar, 35, sustained serious injuries when their parked truck was attacked by a mob with a petrol bomb at Udhampur town on the Jammu-Srinagar highway.
The attack, allegedly by a Hindu mob, took place in the aftermath of a beef party hosted by independent legislator Engineer Rashid in Srinagar.
As news of the death in Delhi spread, mobs took to the streets in the southern district of Anantnag in the Kashmir Valley and blocked the Jammu-Srinagar highway by burning tyres.
The highway is the only road link between the Kashmir Valley and the rest of India.
They also shouted slogans against the government, and pelted stones at security personnel who tried to disperse them, witnesses said.
Hurriyat chairman Mirwaiz Umar Farooq said the government was to blame for Bhat's death as it failed to provide security to the truckers.
The separatists called for a shutdown in the Kashmir Valley on Monday.
Both the victims of the attack were flown to Safdarjung Hospital which specializes in treating burn injuries.
Jammu and Kashmir Chief Minister Mufti Muhammad Sayeed had visited them at the hospital three days back.