An investigation into a missile strike carried out by US-led forces in Afghanistan earlier this week has found that 13 civilians were among 16 people killed, the US military has said.

The military made the admission on Saturday, after originally saying that 15 opposition fighters had been killed in the strike in the Gozara district of Herat province.

Afghan officials insisted all along that six women and two children were among those killed.

Following Afghan outrage over the attack, US generals undertook an investigation, travelling to Gozara and talking to locals there.

The generals said some anti-government fighters had also been killed in the strike.

Michael Ryan, a US brigadier general, said that the investigation proved how seriously the US takes civilian casualties.

The US has come under increasing criticism over the past few months over the deaths of civilians in military operations in Afghanistan.

Hamid Karzai, the Afghan president, said that rising civilian deaths was a source of tension between Kabul and Washington.

There are currently 80,000 US and Nato soldiers in Afghanistan, battling Taliban and al-Qaeda fighters.

Barack Obama, the US president, announced last week that an additional 17,000 troops would be sent to the country, in addition to the 38,000 already stationed there.