Leading Pakistani human rights advocate Asma Jahangir has died, her family said on Sunday, in a major blow to the country's embattled rights community. She was 66. The lawyer and co-founder of the Human Rights Commission of Pakistan died of cardiac arrest, according to her sister. "Unfortunately we have lost her," Hina Jilani, also a prominent rights activist and lawyer, said. Jahangir's daughter Munizae said the family was waiting for relatives to return to their hometown of Lahore before announcing funeral arrangements. Prime Minister Shahid Khaqan Abbasi expressed grief at Jahangir's death, praising her contribution to upholding the rule of law and safeguarding human rights. Jahangir's supporters and former opponents alike took to social media to offer their condolences and express shock at news of her death. "The best tribute to her is to continue her fight for human rights and democracy," tweeted Pakistani Nobel Peace Prize laureate Malala Yousafzai, adding she had met Jahangir just last week in Oxford. Journalist Wajahat Khan said on Twitter that he and many others did not agree with some of her views. "But she was a titan. And one of the brightest and bravest ever produced by this country." Jahangir's death was also mourned across the border in India, where several film industry celebrities, including the veteran director Mahesh Bhatt, the actress Shabana Azmi and the screenwriter-lyricist Javed Akhtar paid tribute on Twitter. Bhatt described her as "an extraordinary woman who fought for ordinary people". Outside of Pakistan, Jahangir served as UN special rapporteur on human rights in Iran. In 2014 she received France's highest civilian award and Sweden's Right Livelihood Award, for her decades of rights work. Few Pakistani rights activists have achieved the credibility of Jahangir. She braved death threats, beatings and imprisonment to win landmark human rights cases while standing up to dictators. The rights commission which she helped create made its name defending religious minorities and tackling highly charged blasphemy accusations along with cases of "honour" killings - in which victims, usually women, are murdered by a relative for bringing shame on the family. There is still terrible violence against women, discrimination against minorities and near-slavery for bonded labourers, Jahangir said during an interview in 2014, but human rights have made greater strides in Pakistan than may be apparent. "There was a time that human rights was not even an issue in this country. Then prisoners' rights became an issue," she said. "Women's rights was thought of as a western concept. Now people do talk about women's rights - political parties talk about it, even religious parties talk about it." Jahangir secured a number of victories during her life, from winning freedom for bonded labourers from their "owners" through pioneering litigation, to a landmark court case that allowed women to marry of their own volition. She was also an outspoken critic of the powerful military establishment, including during her stint as the first female leader of Pakistan's top bar association. Jahangir was arrested in 2007 by the government of then-military ruler Pervez Musharraf and held under house arrest. In 2012 she claimed her life was in danger from Pakistan's feared Inter Services Intelligence spy agency.