Three British soldiers were killed today in Helmand province in Afghanistan, extending the rising trend of green on blue killings where Afghan security forces turn their weapons on NATO personnel. Because NATO systematically under-reports green on blue attacks by only reporting on attacks in which NATO personnel are killed, not when they are injured or escape injury, we have only an incomplete picture of how rapidly the attacks are growing.

Reuters brings us the details of today’s killings:

An Afghan policeman shot dead three British soldiers at a checkpoint in southern Helmand province on Sunday, Afghan officials said, the latest in a chain of increasingly frequent rogue killings.

A fourth British soldier was also injured, provincial governor spokesman Daoud Ahmadi said of the attack, which could further erode trust between NATO and the Afghan forces they train before most foreign combat troops leave in 2014.

Note that this report cites Afghan authorities on the attack and includes the fact that a fourth British soldier was wounded. That contrasts with the AP report in the Washington Post, where we only learn about the deaths:

Three British soldiers were killed in southern Afghanistan on Sunday by a man dressed in the uniform of the country’s police force, Britain’s defense ministry said in a statement Monday.

The ministry said two soldiers from the 1st Battalion Welsh Guards and one from the Royal Corps of Signals were killed in an incident at Checkpoint Kamparack Pul in the Nahr-e Saraj district of Helmand province.

The soldiers were part of a police advisory team which had visited the checkpoint to conduct a shura — a meeting of village elders. Defense officials said in a statement that a man wearing the uniform of the Afghan National Civil Order Police opened fire as the soldiers were leaving the checkpoint. They received first aid at the scene but died from their injuries.

It would appear that Britain’s defense ministry is adhering to the same policy as NATO, which the AP’s Robert Burns reported earlier discloses only green on blue deaths, not injuries or attacks which do not produce deaths or injuries:

 The military is under-reporting the number of times that Afghan soldiers and police open fire on American and other foreign troops.

The U.S.-led coalition routinely reports each time an American or other foreign soldier is killed by an Afghan in uniform. But The Associated Press has learned it does not report insider attacks in which the Afghan wounds — or misses — his U.S. or allied target. It also doesn’t report the wounding of troops who were attacked alongside those who were killed.

Such attacks reveal a level of mistrust and ill will between the U.S.-led coalition and its Afghan counterparts in an increasingly unpopular war. The U.S. and its military partners are working more closely with Afghan troops in preparation for handing off security responsibility to them by the end of 2014.

For this year compared to the same period last year, the number of deaths is similar, but the number of incidents leading to deaths is up. There have been 18 attacks involving fatalities, with a total of 26 deaths so far this year. For the same period last year, there were 24 deaths but they occurred in only 11 attacks according to NATO figures. Burns’ report brings us the figures from previous years:

Last year there were 21 fatal attacks that killed 35 coalition service members, according to ISAF figures. That compares with 11 fatal attacks and 20 deaths the previous year. In 2007 and 2008 there were a combined total of four attacks and four deaths.

In scrambling to provide the best possible explanation for the growing trend of Afghan forces killing NATO forces, the Reuters report relays this information from NATO:

But NATO commanders argue the growing number of shootings is in proportion to the growing size of Afghan security forces toward an eventual 352,000 target.

This argument does NATO no favors at all. It suggests that NATO has learned nothing from previous attacks and that in the efforts to meet their aggressive targets for training and deploying Afghan forces, NATO will have to accept a fairly constant percentage of those troops as likely to turn on NATO forces.