A bomb has exploded near a school in western Afghanistan, wounding 21 people many of them young students, a provincial official says.
Ambulances rushed to the site and took the wounded to nearby hospitals, said Abdul Jabar Shahiq, head of the health department in Farah province.
At least 10 of the wounded were students at the school between the ages of 7 and 13, he said.
He added that three of the wounded were in critical condition.
No one immediately claimed responsibility for the attack.
The bombing came three days after a powerful suicide truck bomb struck a guesthouse in eastern Afghanistan killing 21 people and wounding 90 others.
Most of the casualties in that attack in Lagor province were high school students.
No one has claimed responsibility for the late Friday night bombing in Pul-e-Alam, the capital of Logar.
The attack comes two days after the remaining 2500 to 3500 US troops officially began leaving the country.