Sheikh Hamad bin Khalifa Al-Thani, seen here as Amir of Qatar addressing the United Nations on Sept. 25, 2012, died Sunday at the age of 74. File Photo John Angelillo/UPI | License Photo

July 13 (UPI) -- Former Emir Sheikh Hamad bin Khalifa Al Thani, the ruler of Qatar from 1995 until abdicating in favor of his son in 2013, has died, the emir's office said. He was 74.

Hamad died Sunday morning, Qatar's Amiri Diwan said in a statement.

No cause of death was disclosed.

A four-day mourning period, starting Sunday, was declared by the Amiri Diwan, which stated work at ministries, government agencies and public authorities will be suspended from Monday and resume on July 19.