Lt. Dennis van Uhm, 23, was among two Dutch soldiers killed and two wounded in the explosion, 12 kilometers (7 miles) northwest of the Dutch military base in Uruzgan province known as Camp Holland, said spokesman Lt. Gen. Freek Meulman. The second fatality was not fully identified.
The soldiers' vehicle was returning to base after a large reconnaissance mission in the area, where they face Taliban insurgents, the military said.
"There is no reason to believe that the roadside bomb attack was directed at Lt. Van Uhm," Meulman said.
There was no immediate comment from Gen. Peter van Uhm, who took up his task as overall commander at a ceremony in the courtyard of the Dutch parliament complex on Thursday, succeeding Gen. Dick Berlijn.
"This morning I asked Gen. Van Uhm, the military commander, to concentrate on his personal situation," Defense Minister Eimert Van Middelkoop told reporters at the hastily called news conference. "The contrast between yesterday's festivities ... could not be starker."
Taliban insurgents probably planted the roadside bomb, also known as an improvised explosive device, or IED.
"IEDs are a weapon often used by the Taliban," said Meulman. "We can get rid of most of the threat, but you cannot totally eliminate the danger."
The casualties bring the death toll of Dutch soldiers to 16 since the Netherlands began contributing combat forces to the International Stabilization Force in Afghanistan in August 2006. The Dutch have 1,650 troops in southern Afghanistan.