Governor Arsala Jamal was reading out a message to the locals following the Eid al-Adah prayers. At that moment, an improvised explosive device (IED) planted under the tribune was detonated, killing Jamal at the scene," provincial government spokesman Din Mohammad Darwish told Xinhua.
Fifteen people were injured in the incident which took place around 8.45 a.m. in Pul-e-Alam, some 60 km south of national capital Kabul.
The injured were shifted to a hospital where five of them were in critical condition.
Security was beefed up across the country since Monday as the war-weary Afghans celebrate the Muslim's biggest festival of the Eid al-Adah with a four-day holiday since Monday.
No group has claimed responsibility for the attack but the Taliban insurgent group is likely behind such attacks.
The Taliban, who ruled the country before they were ousted by a US-led invasion in late 2001, renewed armed insurgency, staging ambushes and suicide attacks, killing combatants as well as civilians.
Recently, Afghan officials and pro-government figures have been repeatedly targeted by the Taliban. Over a dozen Afghan officials have been killed since Sep 1 this year in targeted killings in the war-hit country.
The UN Assistance Mission in Afghanistan recently reported that over 1,310 Afghan civilians were killed and more than 2,500 wounded in acts of terrorism and violence in the first half of this year, a 23 percent rise in overall civilian casualties compared to last year.