Unicef Executive Director Henrietta Fore has voiced deep concern about Afghan girls, increasingly, at risk of child marriage in the war-torn country.

"We have received credible reports of families offering daughters as young as 20 days old up for future marriage in return for a dowry," she said in a statement.

Even before the latest political instability, Unicef's partners registered 183 child marriages and 10 cases of selling of children over 2018 and 2019 in Herat and Badghis provinces alone, reports Xinhua news agency.

The children were between six months and 17 years of age, she said.

The UN agency estimates that 28 per cent of Afghan women aged 15-49 years were married before the age of 18.

The Covid-19 pandemic, the ongoing food crisis and the onset of winter have further exacerbated the situation for families, forcing them to make desperate choices, such as putting children to work and marrying girls off at a young age.

As most teenage girls are still not allowed to go back to school, the risk of child marriage is now even higher, said Fore.

Unicef is working with partners to raise communities' awareness of the risks for girls if they are married early. Child marriage can lead to a lifetime of suffering. Girls who marry before they turn 18 are less likely to remain in school and more likely to experience domestic violence, discrimination, abuse and poor mental health. They are also more vulnerable to complications in pregnancy and childbirth, she said.

It has started a cash assistance program to help offset the risk of hunger, child labour and child marriage among the most vulnerable families. The fund plans to scale up this and other social services programs in the months to come.

Unicef will also work with religious leaders to ensure that they are not involved in the "Nikaah" (the marriage contract) for young girls, she said.

"But this is not enough. We call on central, provincial and local authorities to take concrete measures to support and safeguard the most vulnerable families and girls. We urge the de facto authorities (Taliban) to prioritise the reopening of schools for all secondary school girls and allow all female teachers to resume their jobs without any further delays.

"The future of an entire generation is at stake," said the statement.