(KABUL, Afghanistan) -- Four American soldiers were killed by a roadside bomb in Southern Afghanistan.
The bomb, reportedly a suicide vest attack, was set off while the soldiers were on a joint patrol with Afghan forces.
This attack comes as United States and Afghan officials have reached an impasse over a long term security agreement, as the nations are unable to decide how many foreign troops should stay in the country after the war ends in 2014.
Roadside bombs are one of the top killers in Afghanistan, killing and injuring thousands of Afghans every year.
A total of 132 foreign troops have been killed this year, including more than 100 Americans.
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