KABUL (BBC) - Afghan President Hamid Karzai has said the Afghan people are "hurt and saddened" by the deaths of a number of civilians in a NATO air raid.

NATO has confirmed that at least 12 civilians were killed in an air strike targeting Taleban militants on Tuesday.

But the government said initial investigations suggested 25 civilians died in the raid in south Afghanistan. On Friday, 14 people died in Uruzgan province when their bus struck a mine, officials said.

The dead were mainly children and old people traveling to a picnic in celebration of the Muslim holiday of Eid al-Fitr festival marking the end of Ramadan, a local official said.

A NATO spokesman said it was not clear if the mine was old or had been planted recently by insurgents.

Mr. Karzai responded to Tuesday's deaths during a news conference at the presidential palace.

"We share solidarity with the families of the victims and the people of Afghanistan are hurt and saddened by this incident,” he said.

He called on the international community to help strengthen Afghanistan's forces - particularly to help develop an air force - in order to “prevent these sorts of incidents from happening again”.

NATO has said 48 Taleban fighters were killed in three raids in Kandahar province on Tuesday, but the Taleban have denied losing any men.

'Things go wrong'

Local police and officials said more than 40 people were killed in one of the raids, Afghan interior ministry spokesman Zmarai Bashiry told the BBC.

Other local officials put the death toll at between 60 and 85.

NATO forces are the main component in ISAF, the international force deployed in Afghanistan. A spokesman, Capt Andre Salloum, told AFP news agency: “As soon as the battle ended, troops on the ground were able to identify 12 civilians.”

NATO forces were working with the Afghan defense ministry to conduct further investigations, he added.

Another NATO spokesman, Mark Laity, said the troops sought to take maximum care to avoid civilian casualties.

“We've got tight rules of engagement but sometimes things go wrong...” he said.

“President Karzai quite understandably and correctly wants us to show maximum care - that's what we do.”

Deadly 'mistakes'

Residents in Panjwayi say the bombing began on Tuesday and continued into the night, during the Eid al-Fitr festival.

One local man who did not want to reveal his name said 20 members of his family had been killed and 10 injured.

“Anyone can come here to see our homes and area. There are no Taleban here. We all are nomads living in tents,” he said. “Each time they say that it was a mistake. They have destroyed us all in such mistakes. For God's sake, come and see our situation."

Karzai under pressure

A team of tribal and community elders would hold an inquiry, Karzai's office said.

It said Karzai's investigators would make suggestions on how to prevent such “unfortunate” incidents in future and ensure better co-ordination with foreign forces.

Karzai has been under mounting pressure over civilian deaths. He has repeatedly urged foreign forces to exercise more caution.

But correspondents say the fact that such incidents keep happening is eroding public confidence in his ability to pressure the international forces which support his government.

Last week, up to 21 civilians were killed in two NATO operations in Kandahar and neighboring Helmand province.

Hundreds of people have been killed in Afghanistan this year, the bloodiest since the Taleban were removed from power by U.S.-led forces in 2001.