Dawn columnist and human rights advocate I.A. Rehman passed away in Lahore on Monday at the age of 90.

His funeral will be held at Masjid Al Quds A-1 Society Township near LRBT hospital after Isha prayers.

Rehman left behind three sons and two daughters. His wife had passed away earlier in 2015.

According to his family, he was diabetic and suffered from high blood pressure.

According to the Human Rights Office, Rehman was born in India in 1930 and served as an editor for several influential publications. He was also a founding member of the Pakistan-India People's Forum for Peace and Democracy.

As director of the Human Rights Commission of Pakistan (HRCP), he contributed to raising awareness about rights and fundamental freedoms.

For his remarkable struggle for human rights in Pakistan, he was also honoured with an award by the New York human rights organisation, Human Rights Watch.

Rehman started working at a young age, according to human rights activist and former chairperson of the HRCP Zohra Yusuf. She said that Rehman worked as editor of the Pakistan Times before joining the HRCP in the early 90s, first as director and later as secretary general.

Tributes poured in from all quarters as news of Rehman's passing spread.

Foreign Minister Shah Mahmood Qureshi said Pakistan has lost a "true icon".

"A staunch advocate and activist for human rights and an intellectual, Rehman sahib leaves behind a rich legacy that speaks of tolerance, inclusion, equality and dignity," he said.

Human Rights Minister Shireen Mazari also expressed her condolences, saying Rehman was a "unique personality ... who stood by & struggled steadfastly for what he believed in".

PPP Senator Sherry Rehman said she was "shocked and immeasurably saddened" to hear of the journalist's passing.

"He was an icon of integrity, standing steadfast for every single fundamental right, every single democratic value in the worst of times. Pakistan will not be the same without him," she said.

Lawyer Jibran Nasir called Rehman a "teacher, mentor and inspiration to many who always stood to defend human rights through during the darkest times and under the most oppressive regimes in our country's history".

Former special assistant to the prime minister on health Dr Zafar Mirza said Rehman was like "human conscience personified".

In a statement, the HRCP called Rehman a "titan of human rights" and said that his "conscience and compassion were unparalleled".

"Even after his retirement from the HRCP, he remained a constant source of wisdom and advice, and a mentor to many. We will carry his legacy forward as he would have wished us to," the HRCP said.

Journalist Syed Talat Hussain said Rehman was to journalism what "constitutions are to civilised countries".

"Every time we needed guidance we looked him up and he showed us the way. A beautiful soul, a great man," he said.

Journalist Asad Hashim said Rehman was one of Pakistan's "foremost human rights defenders and a key part of all of the incredible work that the HRCP does".

"A tremendous loss for all Pakistanis, not just progressives and those who work in the human rights space," he said.