A roadside bomb exploded Saturday near a convoy of German troops in northern Afghanistan, a day after German military commanders ordered a NATO airstrike in the region, killing up to 90 people, many of them civilians.
Authorities say the blast damaged vehicles, but there are no report of any serious injuries from Saturday's explosion.
NATO is calling for an investigation of Friday's air strike that blew up two fuel trucks in a massive explosion.
The pre-dawn strike was ordered by German military commanders after fuel trucks that had been hijacked earlier by Taliban militants were spotted on a river bank in the Northern Kunduz province, surrounded by what appeared to be insurgents, in the process of unloading the tankers.
German officials say the order to attack was given because the trucks could be used as weapons in a suicide attack against nearby German troops.
Afghan President Hamid Karzai and the NATO command in Afghanistan are promising full investigations into the civilian deaths.
Mr. Karzai issued a statement saying "targeting civilians is unacceptable."
Provincial officials say the strike killed 56 Taliban militants and a large number of civilians, including children who had been called to the area by the Taliban members to remove fuel from the tankers.
An Interior Ministry spokesman (Zemerai Bashry) said the government is working to confirm civilian casualties.
White House spokesman Robert Gibbs expressed concern about the reports of civilian deaths.
Afghan civilian deaths during foreign military operations have caused resentment among the public.
U.S. Army General Stanley McChrystal ordered U.S. and NATO troops in July to limit the use of air strikes to try to reduce such casualties.
U.S. military commanders say protecting Afghan civilians and providing security is a focal point of the Obama administration's revamped strategy in Afghanistan.