Three members of the NATO-led International Security Assistance Force were killed by a roadside bomb in southern Afghanistan Tuesday, ISAF said in a statement.
A spokesman declined to give any further details about the attack, which came a day after a civilian cargo plane crashed at Bagram airfield north of Kabul, killing all seven crew members.
"Three International Security Assistance Force service members died following an improvised explosive device attack in southern Afghanistan today," the statement said without stating the nationalities of the victims, in line with policy.
There was no immediate claim of responsibility but Taliban militants frequently use roadside bombs against US-led foreign troops and their Afghan allies.
Afghan police and soldiers are taking over responsibility for security, but there is growing concern over the war-torn country's prospects after 2014 when all foreign combat deployments will finish.