A suicide bomber killed 10 civilians and wounded at least 30 others in the southern Afghan province of Paktia on Sunday, the Interior Ministry said.
Paktia governor Rahmatullah Rahmat said the bomber struck as a convoy of foreign forces was passing through a street market in the city of Gardez, about 100 km (60 miles) south of the capital Kabul.
A spokesman for the International Security Assistance Force, which leads thousands of foreign troops in the country, said there were casualties among its forces at the scene but no deaths. "Unfortunately we have a report today that at 9:40 a suicide bomber blew himself up in the Gardez roundabout," an Interior Ministry statement said.
"Ten civilians were martyred and about 30 others were wounded." Taliban insurgents have stepped up attacks after a traditional winter lull in fighting. The Taliban has said it has trained hundreds of suicide bombers.
A spate of attacks this week followed the death of the insurgents' top operational commander, Mullah Dadullah, in a raid last weekend that was considered the biggest blow to the Taliban since they were driven from power in 2001.
The Taliban claimed responsibility for a suicide bombing on Saturday in a crowded market in the northern city of Kunduz. Nine people, including three German soldiers, were killed.