Also on Wednesday, a district governor in the same province survived a suicide attack close to his vehicle.
A man detonated his explosives close to the vehicle of the official from Paktika, which is on the border with Pakistan.
The bomber was the only individual to die in the attack.
Elsewhere, police foiled a suicide attack on Wednesday when they seized a man in the province of Kabul with explosives strapped to his body, Zalmay Khan, deputy police chief, said.
Wednesday's troop fatalities occurred as they were travelling in an army vehicle along a dirt road in the Waza Haw district of the province of Paktika.
The Afghan soldiers were travelling in a 10-vehicle convoy, said the army's General Murad Ali.
The powerful blast destroyed their vehicle, leaving seven soldiers dead and one wounded.
Taliban fighters use roadside bombs and have launched suicide bombings at Afghan security forces and thousands of foreign troops in the country assisting them.
Despite a crackdown by Nato forces in Afghanistan's Helmand province, Taliban fighters maintain a strong presence in the region.
Nato's Operation Achilles is into its seventh week but is meeting fierce resistance from the Muslim fighters.
|Taliban fighters possess significant amounts|
of explosive for anti-tank bombs
A team featuring James Bays, Al Jazeera's Afghanistan correspondent, met some Taliban fighters in Helmand province standing on top of a burnt-out Nato military vehicle.
A cameraman attached to Bays' team was taken to a separate area where the Taliban showed him a store-room of explosives, which were in the process of being converted into anti-tank bombs.
The Taliban fighters also said they possess anti-aircraft weaponry, although they did not permit Al Jazeera to film such equipment.
"Thanks to God we have good guns ... we are ready all the time to face them [Nato and Afghan government forces] in a battle," one Taliban fighter said.
On Tuesday, a police vehicle was ambushed by fighters in the province of Herat, killing four officers and wounding two, Noor Khan Nekzad, a spokesman for the provincial police chief, said.
Earlier this week, two separate roadside bombs killed eight Afghan intelligence agents, one soldier and one driver in the eastern province of Laghman.
And on Monday a roadside bomb killed two policemen in southern province of Zabul. On Sunday, fighters beheaded another intelligence agent in the neighbouring province of Ghazni.
Last week, a suicide bomber killed 10 policemen and wounded 40 others in the northern province of Kunduz.