A US sergeant on deployment in Afghanistan went on a civilian killing spree in a remote village in southern Afghanistan over the weekend, murdering 16 people — including nine children.

Of that 16, 11 bodies were gathered into a pile and set on fire by the man, including four girls who were under six years old. Five others were injured.

Apparently acting alone, the sergeant walked the few kilometres from his base to a village in the Panjwai district and then to nearby houses, where he broke into three homes and shot their occupants. The man was part of a village stabilisation operation, and previously served three military tours of Iraq. He arrived in Afghanistan last December and is married with two children, and allegedly recently suffered a nervous breakdown.

The attacks have further heightened tensions between US and Afghanistan officials, already strained after a decade of war.

“The devastating, unexplained attack deepened the sense of siege for Western personnel in this country, as denunciations brought a moment of unity to three major Afghan factions: civilians, insurgents and government officials,” say Taimoor Shah and Graham Bowley in The New York Times.

Afghanistan correspondents Sami Yousafzai and Ron Moreau reported in The Daily Beast on how locals reacted:

“Today, a group of village women gathered to weep at one home where four family members were gunned down. Outside, there were several quiet processions of grieving villagers and remembrances for the victims. Tribal and village leaders urged calm, and people in Panjwai largely heeded the call.”

After ten years of war, Afghans are accustomed to civilian killings and don’t react as violently as they recently did to news of the Koran being destroyed by US soldiers, Joshua Foust from the American Security Project think tank told the Global Post:

“‘Afghans protest when something is shocking and surprising,’ said Joshua Foust … ‘But this is something that they are used to and expect. They consider all civilian deaths criminal. This is just more of the same.’

It may seem counter-intuitive that Afghans will take to the streets, kill or injure themselves and damage their own property, to protest an insult to their religion, but maintain relative calm when their loved ones are killed.”

Al Jazeera interviewed a number of Afghan locals — including a cab driver, a former army colonel and a shopkeeper — for their take on the murders.

Battlefield stress could have triggered the sergeant’s killings, an unnamed army psychiatrist tells Time’s Mark Thompson.

“‘There’s a lot of death,’ says the Army psychiatrist, ‘and all the Americans there are under a lot of stress. The whole region — it’s the birthplace of the Taliban — is a very dangerous area,’ he adds. ‘If the soldier was going out on patrol, he probably was attacked pretty much every day. If he stayed on the FOB [Forward Operating Base], he was probably being shelled regularly.’ … Almost by definition, the Army doctor says, any American who left the confines of his post in the region in the middle of the night by himself was ‘crazy’.”

This event may just make the Taliban more powerful. Amin Saikal, director of the Centre for Arab and Islamic Studies at the Australian National University and the author of Modern Afghanistan, explains why in The Age:

“As the anti-US and anti-Karzai government feelings escalate, the more they will play into the hands of the Taliban and their supporters, most importantly Pakistan’s notorious military intelligence, ISI, to drive a hard bargain. The Taliban and ISI have never found the situation more conducive to their belief that the final victory is ultimately theirs. All they now need to do is await the substantial drawdown of foreign troops and further ineffectiveness and humiliation of the Karzai government. As one Taliban commander joked: ‘We have the time and the Americans have the watch.'”

Withdrawal of US troops by the end of 2014 remains the US’ Afghanistan strategy, but the timetable for withdrawal of US and allied troops will “certainly be a subject of discussion among heads of state at the NATO meeting in Chicago in May,” said White House spokesman Jay Carney.

The political implications aren’t just international. It could impact Barack Obama’s re-election campaign, since “… rising tensions could make Afghanistan a reelection liability by upending what until now has been more or less a pass for Obama,” says Howard LaFranchi in Christian Science Monitor. “While a majority of Americans have for the past couple of years said the 11-year-old war is not worth the price the country is paying, many Americans have also recently said the president is doing a ‘good or fair’ job of managing the war.”

Secretary of State Hillary Clinton reacted to the news with revulsion: “This is terrible, awful –I can’t even imagine the impact on the families who were subject to this attack and the loss of children in this terrible incident,” said Clinton. “This is not who we are, and the United States is committed to seeing those responsible held accountable.”

The Afghanistan parliament called for a public trial in Afghanistan courts of the US sergeant, but the US government says it will trial him in a military court back home.

The news was greeted with horror by newspaper front pages from around the US: