US Secretary of State Hillary Clinton has apologized for civilian casualties in Afghanistan, promising to seek ways to avoid "the loss of innocent civilian life".

Clinton said Wednesday that the Afghan-based US-led troops would try to prevent civilian casualties in the future after an air attack by the forces on western Afghanistan massacred up to 150 civilians, Reuters reported.

Speaking at the beginning of tripartite talks with Afghan President Hamid Karzai and Pakistani President Asif Ali Zardari, she also offered her 'deep regrets' over the Tuesday carnage which took its toll on the villagers in the Farah province.

"We deeply regret it. We don't know all of the circumstances or causes. And there will be a joint investigation by your government and ours," Clinton said.

The international Red Cross has confirmed that the victims included women and children.

Since its 2001 invasion of Afghanistan, the US military's attacks on alleged militant hideouts on the common border with Pakistan have been incurring considerable civilian fatalities.

Despite the ensuing anti-American sentiment in both countries, US President Barack Obama has assigned 21,000 soldiers and a high number of civilian experts to the Afghanistan-based contingents.

HN/MD