A 10-year-old girl was allegedly forced by her brother to wear a suicide vest and detonate it at a police checkpoint in Helmand province, on the Pakistani border.
"My brothers Zahir and Jabar put a suicide vest on me, removed my green outfit and told me to wear a black outfit, saying my green clothes would get wet while crossing the river. They told me to cross the water and go to that checkpoint and explode it," the girl, only known as Spozhmai, told Reuters.
"They brought me to the river to cross at night; but when I saw the water and coldness I shouted and I said it was cold and I couldn't cross," Spozhmai continued.
Her brother Zahir, known locally as Hameed Sahib, is a local Taliban commander, the country's Interior Ministry said.
Police said they believed Spozhmai's account.
"The guy named Zahir had the suicide vest and escaped, but she was still there and when our commander of the battalion heard her voice, they surrounded the area and brought this girl to their base, and we all heard her story on how she was forced into this action," Colonel Hamidullah Sediqi said.
Some reports said Spozhmai had been captured in the vest and others said her brother Zahir had fled with it.
The local governor said he had started an investigation.
Afghanistan's President Hamid Karzai condemned the use of children in suicide attacks, as it is "against the instructions of holy Islam and the values of Afghan culture".
"Children are the future-makers of the country. They should be taken care of, and education opportunities should be provided for them. They shouldn't be used as a tool for suicide attacks." the president said in a statement.
Karzai ordered the Interior Ministry to eventually give Spozhmai back to her parents after getting assurances from them that the girl will be able to continue her family life like other children.
The Taliban have denied any involvement with the attempted attack.
"We never do this, especially with girls," Taliban spokesman Qari Yousef Ahamdi said.
According to international NGO Human Rights Watch, an eight-year-old girl was killed in central Uruzgan province in 2011 when a bag of explosives the Taliban ordered her to carry to a police checkpoint detonated.