India, July 12 -- Sheikh Hamad bin Khalifa Al-Thani, former emir of Qatar, has died at the age of 74, the country's top government body, the Amiri Diwan, announced on Sunday without mentioning the cause of his death.

Qatar has declared 4 days of public mourning beginning Monday. Government offices and public institutions will remain closed during this period, while flags across the country will fly at half-mast, Doha-based Al Jazeera reported.

Sheikh Hamad, who led Qatar from 1995 until 2013, was seen as a key player in shaping the growth and development of the energy-rich nation.

In a statement, the Amiri Diwan said, "With hearts steadfast in faith in God's decree and destiny, the Amiri Diwan mourns the great loss to the nation of the...