Suspected Taleban fighters are said to have killed five government soldiers and an Afghan aid worker in the south-east of the country.
A spokesman for the authorities said that about 40 suspected Taleban had carried out the attack in Helmand province after crossing the border from Pakistan.
The Afghan civilian worked for an American aid organisation in the province.
A BBC correspondent in the Afghan capital, Kabul, says that attacks on government targets and foreign aid organisations are increasing, despite the presence of a large American force near the city.
He says that recently there have also been attacks on religious leaders who've openly supported the interim government of President Hamid Karzai.
From the newsroom of the BBC World Service