A young Afghan girl has been detained wearing a suicide vest in southern Afghanistan, officials say.

She was held on Sunday night in Helmand province, as she tried to carry out an attack on border police, an interior ministry spokesman told the BBC.

The girl, reported to be as young as eight and thought to be the sister of a prominent Taliban commander, is said to be in a state of shock and confusion.

Police told the BBC she was encouraged to carry out the attack by her brother.

According to interior ministry spokesman Sediq Sediqi, one of the Afghan soldiers spotted the girl wearing a suicide jacket.

But she could not operate the button to detonate the suicide vest or she was arrested before she could carry the attack, the BBC's Bilal Sarwary reports from the Afghan capital, Kabul.

The girl has now been transferred to the provincial capital of Lashkar Gah.