Nato Secretary-General Jaap de Hoop Scheffer pledged today to investigate civilian deaths in Afghanistan.
The rising toll on civilians is putting pressure on Afghan President Hamid Karzai, who, like Mr Scheffer, is in Rome for a conference on the rule of law in his country.
In the latest major incident this weekend, Afghan officials said 45 civilians were killed by an air strike, though the Nato-led International Security Assistance Force set the toll from the pre-dawn raid lower.
"Our opponent mixes and mingles with innocent civilians. They are in a different moral category," Mr De Hoop Scheffer said after meeting Italian Prime Minister Romano Prodi, whose country contributes to the nearly 50,000-strong international mission.
"We do not intentionally kill, they behead people, they burn schools, they kill women and children. Let us not forget," said the Nato chief. He declined comment on the death toll itself.
UN secretary general Ban Ki Moon said civilian casualties, no matter how accidentally they were caused, would only strengthen the Taliban.
Civilian deaths have sparked demands for the expulsion of foreign troops and Mr Karzai's resignation. An Afghan rights group said this week that foreign air strikes had recently killed more civilians than the Taliban and should be cut back.
Violence has surged in the past 17 months in Afghanistan, the bloodiest period since US-led troops overthrew the Taliban government in Kabul in late 2001. Taking a lead from the Iraq insurgency, the Taliban have increasingly resorted to suicide and roadside bomb attacks against foreign troops or government targets.