The incident took place during the spring offensive of the Taliban, the militant anti-government movement.
MORE: http://www.cnn.com/2013/05/21/world/asia/afghanistan-violence/index.html
See also...
At least 7 killed in Kabul violence
http://www.cnn.com/2013/05/24/world/asia/afghanistan-violence/index.html
Top politico killed in northern Afghan attack
http://www.cnn.com/2013/05/20/world/asia/afghanistan-violence/index.html
Bombs kill 9, wound 70 in Afghanistan
http://www.cnn.com/2013/05/17/world/asia/afghanistan-violence/index.html
6 Americans among those killed in Kabul bombing
http://www.cnn.com/2013/05/16/world/asia/afghanistan-violence/index.html
3 coalition troops killed in Afghan bombing
http://www.cnn.com/2013/05/14/world/asia/afghanistan-violence/index.html
