Four US soldiers with the Nato-led force in Afghanistan have been killed by a roadside bomb, officials say.
A government spokesman in the southern province of Kandahar said the soldiers were in a convoy in Zhari district. Several others were reported wounded.
Taliban insurgents announced the start of their spring offensive in March.
The attack is the latest in a series this month on international troops in Afghanistan.
Some 100,000 soldiers are still serving with the Nato-led International Security Assistance Force (Isaf) in Afghanistan, but they are due to be withdrawn by the end of 2014.