The bomber struck in Kunar, one of Afghanistan's most restive provinces and an insurgent stronghold on the border with Pakistan, where Taliban-led militants fighting the Afghan government and US-led troops have rear bases.
"A suicide attacker targeted a gathering of tribal elders in the Asmar district of Kunar today," Bashary told AFP. "Ten people have been martyred and seven others have been injured."
He said the dead included a key local pro-government elder.
The district police chief, Mohammad Shoaib, said the bomber blew himself up after approaching an elder, Malik Zarin, to hug him in greeting.
"The suicide attacker approached them, hugged Malik Zarin and then detonated the explosives strapped to his body," Shoaib said.
The Taliban and other insurgents frequently target pro-government figures as part of their near 10-year campaign against government forces and the roughly 130,000 international troops in Afghanistan.
But the Taliban denied responsibility for Wednesday's attack in a text message sent to AFP.
Last week, the Wall Street Journal reported that Al-Qaeda militants were returning to eastern Afghan provinces such as Kunar and setting up bases for the first time in years, exploiting a pullback of US troops in the area.
In response, the NATO-led International Security Assistance Force (ISAF) denied that Al-Qaeda was staging a "return in force."
The accidental deaths of civilians in international military operations in Kunar in recent months triggered a wave of protests in Afghanistan and highlighted tensions between President Hamid Karzai and his Western backers.