"I can confirm that two Dutch marines have died" while on patrol with Afghan police and army members in the Deh Reshan region around 1100 GMT, ministry spokesman Otte Beeksma told AFP.
Corporal Jeroen Houweling, 29, and private Marc Harders, 23, were killed when the armoured patrol vehicle they were travelling in struck an improvised explosive device.
A third Dutch marine, 21, was seriously injured in the explosion.
Defence Minister Eimert van Middelkoop was "deeply saddened by the loss of these two brave marines," added Beeksma.
"They gave their lives for a better world and a better future for the Afghan people," he quoted the minister as saying.
Around 1,950 Dutch troops are deployed in Afghanistan under the NATO-led International Security Assistance Force (ISAF).
Twenty-three Dutch soldiers have died since the Dutch mission started in 2006.
Dutch troops are set to start withdrawing from Uruzgan in August, to be completed by year-end.
The Dutch government collapsed in February in a spat over whether to extend the deployment.
Published 18 April 2010, 06:01 IST