Afghanistan's president said Thursday that 18 people killed in a NATO airstrike in eastern Afghanistan on Wednesday were all civilians.

NATO has so far said it has no records of civilian deaths from the pre-dawn strike Wednesday on a house in Logar province. The NATO and Afghan troops were going after a local Taliban leader when the international coalition says they came under fire and called in an airstrike on the house.

"This is unacceptable. It cannot be tolerated," President Hamid Karzai said of the strike in Logar. He criticized NATO for not being able to provide an explanation for the vans piled with women and children's bodies that villagers displayed to reporters.

NATO confirmed only militant deaths from the strike but has sent an assessment team to investigate allegations that civilians were killed either alongside or instead of insurgents.

Afghan President Hamid Karzai(left), seen here meeting with with Chinese President Hu Jintao, has criticized NATO for the airstrike. (Mark Ralston/Reuters)

"The reason this team has been dispatched down there is because there is such a discrepancy between what our operational reporting indicates and what Afghan officials on the ground are saying happened," said Maj. Martyn Crighton, a spokesman for the NATO force in Afghanistan.

Villagers displayed 18 bodies at the provincial capital on Wednesday, including five women, seven children and six men. Afghan officials said then that some or all of the dead men were militants. Since no government officials have visited the site of the attack, it was not clear if there might also be additional dead.

Conflicting reports show confusion around raids

Wednesday was a particularly deadly day for Afghanistan as a trio of suicide bombers killed 22 people in the busy marketplace of Kandahar city.

Karzai said in the statement that he was cutting short his trip to China because of the attacks in Logar and Kandahar. He was expected back in Kabul on Friday, said Syamak Herawi, a spokesman for the president.

Karzai's condemnation of the strike and NATO's treatment of it serves as a reminder of the ongoing tension between Afghanistan and its Western allies as U.S. Defence Secretary Leon Panetta visits. Panetta told reporters that he is using the trip — his fourth to the war zone — to take stock of progress in the war and discuss plans for the troop drawdown.

Nighttime raids on militants taking cover in villages have been a repeated source of strained relations between the Afghan government, which says they put civilians in the crossfire, and its international allies, who say such operations are key to capturing and killing insurgent leaders.

A deal signed in April was supposed to resolve the issue by putting the Afghan government in charge of such operations. But Karzai's statement put all the responsibility for Wednesday's strike on NATO.

The conflicting reports of the raid in Baraki Barak district also show the confusion and strife that continue to surround these raids despite the document signed in Kabul. Villagers said that the airstrike hit a house where a number of families had come in from out of town for a wedding party. Afghan police said it was a gathering of militant leaders in the area who had holed up in a village house for the night.