In 1971, at the height of the Bangladesh Liberation War, Kibria, an ethnic Bengali, dissociated himself from the Pakistani foreign service and declared allegiance to the Mujibnagar government.
[6] His father, Shah Imtiaz Ali, was a pioneer in the field of primary education in the greater Sylhet region.
[7] He received training for diplomatic service at the Fletcher School of Law and Diplomacy at Tufts University in Boston, USA and British Foreign Office in London, UK.
On 4 August 1971, he along with his Bengali colleagues, quit the Pakistan embassy and declared allegiance to the interim Bangladesh government.
In 1979, Kibria served as the elected Chairman of the Group of 77 Preparatory Committee for United Nations Conference on Trade and Development V held in Manila.
From May 1981 to March 1992, Kibria held the post of Executive Secretary of UN Economic and Social Commission for Asia and the Pacific (ESCAP).
He started to take in interest in politics and joined Bangladesh Awami League in September as a member of the advisory council.
Kibria was elected Chairman of the Economic and Social Commission for Asia and the Pacific, 1997 annual session.
Kibria's five-year term was marked by economic progress and stability, the only exception being a stock market failure in 1996.
In 2000–2001 the figure rose to 264.91 tons and for the first time in half a century, Bangladesh achieved food self- sufficiency.
[citation needed] On the afternoon of 27 January 2005, Kibria addressed a political rally at Boidder Bazar primary school, Habiganj.
After the speech, as he was exiting the grounds through the school gate, two Arges grenades exploded in quick succession.
[12] The role of the security forces, government officials and medical personnel of Habiganj spurred controversy.
[13] The family members of Kibria called for a non-violent movement in Dhaka demanding justice.
[16] Kibria regularly wrote columns in national dailies addressing economic and political issues.