US and Afghan investigators are due to give their findings, after probing an incident in which over 40 civilians were killed by US bombs in Uruzgan province.

Certainly, the president expressed to President Karzai that this was a tragic loss

White House spokesman

Afghan President Hamid Karzai and General Dan McNeill, general commander of US forces in Afghanistan, are due to give a joint news conference at 0530 GMT.

On Friday, US President George W Bush has telephoned the Mr Karzai to express his sympathy for the loss of life in Monday's bombing raids by US warplanes.

The Pentagon insists the US planes came under hostile fire.

The BBC's Kate Clark in Kabul says the incident has left Afghans angry and perplexed.

No 'apology'

President Bush spoke to President Karzai for about five minutes, describing the death of Afghan civilians as a tragic loss and passing on his sympathies to the families of those who died.

Sorrowing Afghans are wondering about US actions

Mr Bush then began a weekend break with his family, leaving officials to pass on the details of the phone call.

The word "apology" has not been used in Washington because for now there remain differing accounts of what happened on Monday morning.

Afghan officials say the bombing raid over Uruzgan province killed up to 46 civilians, 22 of whom are said to have been attending a wedding party.

The Americans insist their planes were simply responding to anti-aircraft fire from the ground - much more intense than the scattered gunfire which by tradition follows Afghan weddings.

Both Mr Bush and Mr Karzai have restated their commitment to finding any al-Qaeda fighters who may be hiding in the area.

But the incident has done little for America's public relations in Uruzgan.

The governor of the province has warned of a holy war against the United States if more civilians are killed.