Taliban uses child as suicide bomber

"The use of children and youths who don't know the difference between right and wrong in terrorist attacks is inhumane and against all Islamic principles," the president said.

The suicide bomber detonated a vest packed with explosives inside a bazaar in the Barmal district of Paktika province, 160 miles southeast of Kabul, on the border with Pakistan. The blast killed four civilians and wounded 12, said Mokhlis Afghan, a spokesman for the provincial governor's office.

Among the dead - and the likely target of the attack - was Sher Nawaz, head of a new district council in the Shakeen area of Paktika province, Afghan said.

In the Taliban's announcement on its offensive, it suggested it would try to limit civilian casualties in its operations.

"Strict attention must be paid to the protection and safety of civilians during spring operations by working out a meticulous military plan," it said.

A United Nations report released earlier this year presented evidence that the Taliban was responsible for the majority of civilian deaths in Afghanistan in 2010, and Afghan and NATO officials have repeatedly accused the Taliban of breaking its own rules of engagement.