The US counter-insurgency mission is trying to win local support
Afghanistan's president has criticised US forces for "unilateral operations" in the west which, the government says, killed at least 70 civilians.
A spokesman for the US task force, that operates outside Nato, said an inquiry was under way. The US had initially denied any civilians had died.
Meanwhile, police say 10 civilians have been killed by a roadside bomb in the south of the country.
The victims were travelling in a minibus between Kabul and Kandahar.
Correspondents say roadside bombs in Afghanistan usually set to target security forces, but are often triggered early and kill civilians.
The US operations in the west of the country have led to renewed tensions between President Hamid Karzai and the international forces. Tribal elders said a bomb had been dropped on a large group of mourners at a wake in Herat on Friday.
The Afghan Independent Human Rights Commission said initial findings were that 78 civilians had been killed in the US raid, including women and children, but this could not be fully verified and a delegation was investigating.
Mr Karzai's statement said he had launched an investigation and had ordered various ministries to "prepare a comprehensive plan to prevent civilian casualties" which would be handed over to the coalition.
The US forces initially said they "remained confident" no civilians had been killed, something they said had been verified by Afghan security forces, but later added they were investigating and "every effort is made to prevent the injury or loss of innocent lives".
The BBC's Alastair Leithead in Kabul says the issue of civilian casualties has been a constant source of friction between Mr Karzai and international forces.
The deaths of innocent people not only affects families and tribes of those killed, but impacts on the whole counter-insurgency mission, which is to try to win people's support, not drive them against the government and the international presence in Afghanistan.
A local MP said Afghan security forces had fired on hundreds of people protesting against the raid on Saturday.
He said they had killed at least one person and wounded two others.