KABUL - Up to 3,200 civilians have been killed in NATO and US action in Afghanistan since 2005 but compensation payouts have been far lower than in other global cases, according to research by a US professor.

The use of air power is growing, raising risks for civilians, University of New Hampshire professor Marc W. Herold says in research released on the anniversary of the October 7, 2001 launch of the invasion of Afghanistan.

International troops arrived to topple the Taliban and have remained to fight an insurgency in which civilians are killed in military action and attacks, although the government and militaries involved do not release numbers.

Herold says other groups tracking the civilian cost of the war, such as Human Rights Watch, underestimate the tolls while international military and media attach low value to Afghan life in the accounting of events.

Herold, who runs the Afghan Victim Memorial Project [1], says his research shows between 2,699 and 3,273 civilians were killed in direct action by international forces in Afghanistan from 2005 to so far this year.

His figures, which he says are also underestimates because civilians are sometimes labelled militants by the military and unknown numbers of injured dying, are based on media and nongovernment organisation reports and other research.

"By relying upon aerial close air support attacks, US/NATO forces spare their pilots and ground troops but kill lots of innocent Afghan civilians.

"Air strikes are 4-10 times as deadly for Afghan civilians as are ground attacks," he says.

Herold says the US military gives families of its victims at most 2,500 dollars as a condolence payment -- not "compensation" which would admit wrong-doing.

Canadian per person condolence payments to Afghans since 2006 range from 1,100-9,000 dollars, he says.

This compares to 1.85 million paid for victims of the 1988 bombing of a flight over Lockerbie, Scotland, and 150,000 dollars per victim of a 1999 US bombing on the Chinese embassy in Belgrade that killed three Chinese and wounded 23 other people.