Authorities in India have declared a seven-day mourning period to honor Manmohan Singh as politicians and public paid tributes to the country’s former prime minister widely regarded as the architect of India’s economic reform program.

India announced seven days of state mourning on Friday after the death of former prime minister Manmohan Singh, one of the architects of the country's economic liberalisation in the early 1990s.

A respected economist who rose to prime minister from humble beginnings, Singh stood out in India’s often raucous politics with his quietly dignified demeanor.

A mild-mannered technocrat, Manmohan Singh became one of India's longest-serving prime ministers. He was chosen to fill the role by Sonia Gandhi, the widow of assassinated Prime Minister Rajiv Gandhi.

Prime Minister Narendra Modi recalled his predecessor Dr Manmohan Singh as someone who "made extensive efforts to improve people’s lives," while President Droupadi Murmu remembered him as a "rare politician who also straddled the worlds of academia and administration with equal ease.