Kabul, Afghanistan (CNN) -- Three young civilians in southern Afghanistan were killed by a bomb Friday, NATO's International Security Assistance Force said.
The incident occurred in the Zhari district of Kandahar province, the military said, and it is blaming the casualties on bombs planted by insurgents.
The Afghans -- said to be ages 10, 15 and 20 -- were killed by an improvised explosive device, it said.
In another part of Kandahar province, a civilian was wounded when a car struck an IED, the military said.
"This is a terrible tragedy and demonstrates the indiscriminate killing of civilians from IEDs planted by insurgents. ISAF condemns these acts of terror," said U.S. Army Col. Rafael Torres, ISAF spokesman.
"Our thoughts and concerns are with the victim's families. We'll work with our Afghan partners to find those responsible for these attacks and bring them to justice."