U.S. and Afghan officials have promised a formal investigation into this week's U.S. bombing raid that Afghan officials said killed 48 civilians and wounded 117.

The commander of U.S. forces in Afghanistan has acknowledged that there were civilian casualties in the accidental air attack. General Dan McNeill addressed a joint news conference in Kabul with Afghan Foreign Minister Abdullah to give preliminary findings of a joint U.S.-Afghan investigation.

"Indeed, if innocent civilians died, it had to be an accident. It is not our policy to target people who are innocent and not part of this fight," General McNeill said.

The general said U.S. planes had come under anti-aircraft fire in the Uruzgan province. Local Afghans said they were merely firing rifles into the air to celebrate a wedding party, in line with local traditions.

General McNeill promises a formal investigation will be conducted. "There has been injury and loss of life to innocent civilians. We will want to know why, and if indeed things did not work correctly, we will want to know fixes. We will want to put in place those fixes," he said.

Afghan Foreign Minister Abdullah said the investigation into the deadly attack might take some time. But he said such tragic loss of life among civilians should be prevented in the hunt for remnants of Taleban and al-Qaida fighters.

"What is important is the proper investigation has to be conducted and the results have to be made public and lessons have to be drawn, in order to prevent those events from happening again," Mr. Abdullah said.

President Bush has offered sympathies to the families of Afghan civilians killed in the attack. He telephoned Afghan President Hamid Karzai on Friday to discuss the fact-finding mission into the incident and the fight against terrorism.