The US-led coalition says four of its troops were killed in a roadside bomb attack in eastern Afghanistan.
The coalition did not identify the nationalities of the victims, but the majority of troops in eastern Afghanistan are American. One Afghan national was also killed in the blast.
The number of US military deaths in Afghanistan in 2008 has already surpassed the record 111 deaths the US suffered last year.
The coalition did not say where the Wednesday attack took place or provide any other details.