The leader of Jammu and Kashmir and an ally of Prime Minister Narendra Modi died on Thursday, bringing political uncertainty to the disputed region at the heart of tension between India and Pakistan. Mufti Mohammad Sayeed, 79, died of a respiratory infection after spending the last two weeks in hospital in New Delhi, a spokesman for his Peoples Democratic Party (PDP) said. "Mufti Sahab's demise leaves a huge void in the nation and in J&K, where his exemplary leadership had a major impact on people's lives," Modi said in a message on Twitter. The Muslim-majority region is claimed in full, but ruled in part, by India and Pakistan and a high-level dialogue between the nuclear-armed neighbours only resumed recently after India agreed to add it to the agenda of talks that seek to reduce border tension and contain militant attacks. Modi and his Pakistani counterpart, Nawaz Sharif, who met last month, are struggling to keep the talks on track after a militant attack last weekend on Pathankot air base near the border. India says the attack was carried out by Kashmiri separatists operating from Pakistan. Sayeed, who was appointed to lead the state for a second time last year, formed an unlikely partnership with Modi's Hindu nationalist Bharatiya Janata Party (BJP) to govern state for the first time, according to a news agency.