According to Afghan TOLO news agency citing local officials, gunmen have stormed the 'Save the Children' office in Jalalabad in the Nangarhar province.
A spokesman for the provincial governor cited by the media outlet said that the fighting between the attackers and security forces is underway.
Officials confirmed that one suicide bomber detonated explosives at the gate of the building.
"The there was a blast and the target was Save the Children," provincial government spokesman Attaullah Khogyani said.
According to health officials, at least 11 people have been injured in the attack.
TOLO news agency cited eyewitnesses as saying that children attending a nearby school have been seen running from the area amid gunfire.
Save the Children is a London-based international organization that promotes children's rights, provides relief and helps support children in developing countries.