At least 30 civilians have been killed in US-led air strikes against insurgents in Afghanistan.

Afghan President Hamid Karzai has ordered his government to investigate the reports of high civilian casualties during strikes yesterday in the western province of Farah.

The Red Cross claims more than 100 may have been killed the attack.

'We confirm that the number of civilians killed in this operation is way more than 30 but we do not have an exact figure at this stage,' Farah province police chief Abdul Ghafar Watandar said.

It is one of the highest civilian death tolls from Western military action since the invasion of Afghanistan in 2001.

Farah province governor Rohul Amin said the Taliban was in control of the area 600km from Kabul making it difficult to verify numbers.

'The area is under Taliban control. We have not been able to get figures on civilian casualties,' he said.

The International Committee of the Red Cross in Kabul said it had sent a team to investigate after locals appealed for help.

'Their impression was that there were dozens of dead,' ICRC spokeswoman Jessica Barry said.

'We can absolutely confirm that there are civilian casualties,' she said. 'Dozens of people were killed, including women and children.'

Mr Karzai said in a statement from Washington that he would raise the issue with US President Barack Obama when he meets him later today.

US Secretary of State Hillary Clinton said that the White House deeply regretted the loss of civilian life.

'We don't know all of the circumstances or causes. And there will be a joint investigation by your government and ours,' she told a meeting with President Karzai.

In Kabul UN envoy Kai Eide said he was 'seriously concerned' and was in close contact with the top US military commander in Afghanistan, General David McKiernan, as investigations proceeded.