Four soldiers with the NATO-led International Security Assistance Force (ISAF) were killed Friday by separate explosive device blasts in southern Afghanistan, said an ISAF statement released on Saturday.

However, it did not specify the information of nationalities of victims in the light of ISAF policy.

Meanwhile, the Danish military said that three Danish soldiers have been killed and one injured when their vehicle was hit by a roadside bomb in southern Afghan province of Helmand.

Around 700 Danish troops have been deployed in Afghanistan, most of whom are stationed in the Helmand province under British command while the recent three deaths brought its death toll to 21 since Copenhagen deployed soldiers there as part of NATO's International Security Assistance Force in 2001.

Moreover, one Dutch soldier was confirmed being killed when he stepped on an explosive device during a fire-fight with the Taliban in the southern Afghan province of Uruzgan, said Dutch officials.

Over 1,700 Dutch soldiers have been sent to Afghanistan keeping peace and helping with reconstruction there.

Spiraling conflicts and Taliban-linked insurgency have claimed the lives of more than 5,000 people, with over 286 foreign troops, so far this year, despite over 70,000-strong international troops stationed in strife-torn Afghanistan.