KABUL:  International troops fighting the Taliban insurgents in Afghanistan killed six civilians, NATO said Saturday, a day after conceding that six Afghan soldiers had died in a "friendly fire" incident.

Civilian casualties are an incendiary topic with Afghans, who increasingly regard the presence of international troops in their country as the main cause of violence that has wracked Afghanistan for almost nine years.

A brief statement from NATO`s International Security Assistance Force (ISAF) said "artillery fire from an ISAF unit killed six civilians and wounded several others in Jani Khel on Thursday," referring to a district of Paktia province, south of Kabul.

The dead had been removed before ISAF units had arrived on the scene, ISAF said, and so it was not immediately clear that people had been killed by what it said were "errant rounds".

ISAF had accepted "responsibility for the actions that led to this tragic incident" and apologised, it said.

The statement comes after ISAF said a helicopter patrol in southern Ghazni province had opened fire on a group of Afghan soldiers on Tuesday, after mistaking them for militants planting bombs by a roadside.

Six of the soldiers were killed and another was injured, it said, as a "result of miscommunication" between ISAF and the Afghan army about where the Afghans would be patrolling that night.

While reports of friendly fire incidents are not common in Afghanistan, they add to a perception that the foreign forces fighting the insurgency do not take enough care to avoid killing Afghans, military or civilian.

Command of the 140,000 troops in Afghanistan has just been taken over by US General David Petraeus who is under some pressure to change the rules of engagement, as some soldiers believe they restrict defensive action.

Petraeus has not publicly ruled out making changes, though observers in Kabul said he is unlikely to alter rules he was instrumental in formulating and which are credited with cutting civilian casualties.

The United Nations said in a recent report that most civilian casualties in Afghanistan are caused by the Taliban, using roadside bombs or in suicide attacks.

BDST:1700 HRS, July 10, 2010