By Alastair Leithead
BBC News, Kabul
At least 12 Nato troops have been injured in a single clash with the Taleban close to Kabul on Sunday, it has emerged.
Isaf has been criticised recently over high levels of civilian deaths
The International Security Assistance Force (Isaf) said there was no evidence that civilians were killed or injured in an air strike during the fighting.
A provincial police commander said three civilians had died.
The battle between Isaf soldiers and the Taleban took place in Wardak province, which borders Kabul.
The deputy provincial police chief, Asif Bandwal, said a roadside bomb attack on an international convoy had started the fight and that three civilians had been killed and seven injured when air support was called in.
He said five Taleban fighters were also killed and two wounded.
But the Isaf spokesman, Maj Charles Anthony, denied there had been any roadside bomb attack, and that there was some confusion over what happened.
But he did confirm that "around a dozen" Nato soldiers had been injured in the battle.
The initial report from another Isaf spokesman was that 14 troops had been wounded.
"I'm not saying it's 100% out of the realms of possibility, but we have still not found anything up to this point that would lead us to believe there were any civilian casualties on the ground," Maj Anthony said.
The issue of civilian casualties has been a constant source of tension between international forces and the Afghan government, with President Karzai criticising foreign troops for not taking enough care to prevent mistakes while fighting the Taleban insurgency.