KANDAHAR, Afghanistan - Any possible peace deal with insurgents will be almost impossible to achieve in Afghanistan until the country comes to grips with the war crimes that have bloodied its recent past, says Canada's ambassador to Kabul.

Reconciliation in this country, torn asunder by decades of fighting, will never firmly take hold until there is some form of transitional justice, William Crosbie said in an interview.

There are published reports that the Taliban's Mullah Omar is willing to negotiate peace with western countries, a notion that is being greeted with skepticism on the streets of Kandahar, which is reeling from a recent wave of renewed violence.

One teenager died and four others were injured Monday when a donkey cart exploded at a police checkpoint in the city.

The report in Britain's Sunday Times follows direct negotiations last month between President Hamid Karzai and representatives of another insurgent group, Hizb-i-Islami.

Afghanistan's violent insurgency is made up of three groups: The Taliban in the south; Hizb-i-Islami throughout most of the country and the Haqqani network, which operates primarily in the east and has deep ties to al-Qaida.

Of the three, the Haqqani network is considered the most radical and has been responsible for training the Taliban in deadlier ambush tactics, including bigger roadside bombs.

There is a hint of optimism among western officials now that two of the three groups are making noises about negotiations in public. Both Hizb-i-Islami and the Taliban have made peace offers before, but always in private and often with unacceptable conditions.

Human rights violations are not limited to insurgents. Afghanistan's parliament is stacked with former warlords, many with blood on their hands, from the country's chaotic civil war in the early 1990s.

"The reality in this country is that the crimes have been committed by so many people from many different sides (to the point) where it's difficult to separate the bad guys from the good guys," Crosbie said in an interview with The Canadian Press.

"Canada has long supported the concept of transitional justice. That is to say, those who have committed atrocities -- not just those who are insurgents -- but those who may be part of the political process now should, in one way or another, account for their actions."

Transitional justice needn't be punitive, Crosbie suggested. Victims in some cases are simply looking for a recognition that harm was done.

"I hear time and again from Afghans, they feel a tremendous sense of injustice for those who are able to carry on a normal life with impunity, despite the crimes they have committed," Crosbie said.

"I recently had someone over and he said, 'You know, ambassador, there is a man who is currently serving in the Wolsei Jirga (lower house of Parliament) who is responsible for the murder of my wife. I don't want that man to be subject to the death penalty, but I want that man to acknowledge what he has done to me."'

The Afghan government in 2005 established, but never implemented, a transitional justice system. The program set a deadline of March 2009 to investigate, document and bring war criminals to justice.

"It was a total disaster," said Ahmal Samadi of Afghanistan Rights Monitor, a human-rights group. "No single criminal was identified; no one brought to justice."

There was no political will among the Karzai government, nor the international community, which did not provide the support and expertise to carry out proper forensic investigations, he said.

Samadi said Afghans are harbouring pent-up anger and frustration.

"The lack of justice has eroded the people's confidence in the post-Taliban era," he said in an interview from Kabul. "The lack of justice has fuelled the return of the Taliban."

And he dismissed notions that the Taliban were serious about giving up their designs on power, despite a pledge Sunday to return to their madrassas and to leave politics to civil society. Not much in their latest proposal is different than what they have demanded in the past, he said.

Things haven't changed much in Kandahar, either.

The city's deputy mayor, Azizullah Earmal, was gunned down Monday night by unknown assailants as he prayed in his neighbourhood mosque.

Earmal's death brings to 18 the number of civic officials and local politicians slain in the city since the Taliban was ousted in 2001, said a spokesman for the provincial governor.

The Taliban conducted a series of targeted assassinations over the last two years and pushed the local government to the brink of collapse last spring.