Story highlights A Brown University report says there have been 149,000 war-related deaths in Afghanistan and Pakistan since 2001

It says that each country has had more than 20,000 civilian deaths

(CNN) Tuesday's militant attack on a group of aid workers in Afghanistan, resulting in nine deaths, is yet another instance of the enormous toll of the ongoing violence in the region.

A new study from the Costs of War project at Brown University estimates 149,000 war-related deaths, with an additional 162,000 serious injuries, in Afghanistan and Pakistan since 2001. And even these numbers don't tell the whole story, which includes significant destruction of infrastructure, displacement of people, and indirect deaths from malnutrition and disease.

Civilian casualties have been particularly high, according to the report, totaling around 26,270 deaths in Afghanistan and 21,500 in Pakistan. The study says that most of the civilian casualties in Afghanistan are caused by militant groups, but the number caused by Afghan and international forces has been increasing since 2012.

The current conflict in Afghanistan dates from 2001. The ruling power at the time, the Taliban , were toppled by a U.S.-led coalition in response to the 9/11 terrorist attacks in the United States. Even though the extremist regime was formally overthrown, it never stopped its insurgency in an effort to regain control.

The turmoil in Pakistan , which has its own Taliban and al Qaeda factions, has become more closely related to that of Afghanistan, with refugees and anti-government militants crossing borders. "It is important for policy makers and others to view the effects and implications of these wars together, because they are so interconnected," said Neta Crawford, the author of the Brown study.

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