The U.S. military in Afghanistan says four coalition and four Afghan soldiers have been wounded in separate explosions in the eastern and southern parts of the country.

A military spokesman says the coalition troops were wounded when their vehicle was hit by a roadside bomb in the Khogyani district of eastern Nangarhar province.  No details of the soldiers' nationalities nor the extent of their wounds were given.

Hours later, in southern Zabul province, a similar explosion wounded four Afghan soldiers on patrol.

Meanwhile, Afghan President Hamid Karzai has ordered an investigation into the killings of eight Afghans, including a child, by U.S.-led coalition forces in Kunar province on Thursday.

Afghan and U.S.-led forces say the dead were suspected al-Qaida militants, but local authorities say they were civilians who had no connection to the terror network.

Some information for this report was provided by AFP, AP and Reuters.