A NATO soldier was killed in a blast on Thursday, while two others lost their lives in another explosion, a foreign news agency cited a statement released by the Western military force.
The alliance, however, did not provide any further detail of the victims.
Roadside bombs and improvised explosive devices (IEDs) are by far the most lethal weapon Taliban militants use against Western alliance, Afghan forces as well as civilians.
According to official figures released by the website iCasualties.org, a total of 411 foreign troops have lost their lives in war-ravaged Afghanistan so far this year.
Last year, nonetheless, remains the deadliest year for foreign military casualties with a death toll of 711.
The increasing number of military casualties in Afghanistan has caused widespread anger in the US and other NATO member states, undermining public support for the Afghan war.