A roadside bomb in eastern Afghanistan has killed 18 people, including at least five women, who were travelling to a wedding party by minibus.

"They were going to attend a wedding party when their minibus was hit by a roadside bomb... which killed 18 mostly females, including children," said local official Shafiq Nang Safai.

The Taliban did not immediately claim responsibility, although it usually denies having a hand in attacks that kill civilians. 

Local officials in the Andar district of Ghazni province said however they believed insurgents were to blame.

Violence has risen in Afghanistan this year as most foreign combat troops prepare to leave by the end of 2014.

Improvised explosive devices are the single biggest killer in the Afghan conflict, causing over a third of civilian casualties in the first six months of the year, according to a UN report.

Although roadside bombs kill civilians almost daily in Afghanistan, the death toll in the latest bombing was unusually high.