Three Danish soldiers were killed and another was seriously injured when their vehicle hit an explosive device in southern Afghanistan, the Danish army said.
The Army Operational Command said yesterday the armoured vehicle was driving with other supply vehicles when it hit a roadside bomb or a mine in the volatile Helmand province.
The soldier who was injured was taken to the Danish Camp Bastion. His condition was not known.
Prime Minister Anders Fogh Rasmussen called it "a sad day for Denmark."
"Today we lost three Danish soldiers in a tragic way. It is the biggest single loss for the Danish engagement in southern Afghanistan," Fogh Rasmussen said.
The victims were all from the Guard Hussar Regiment, a cavalry unit based in Slagelse, 100 kilometers west of Copenhagen. Their names and ranks were not immediately released.
Denmark has about 700 troops serving in the NATO force in Afghanistan. Most are based in Helmand.
Twenty-one Danish soldiers have been killed in Afghanistan since Denmark joined the US-led coalition in 2002.