The ethnic Albanian children were guarding their family's sheep herd Thursday when the blast occurred between two villages near the town of Urosevac , 35 kilometers (22 miles) south of the capital, Pristina.
Police suspect the mine was left behind from Kosovo's 1998-1999 war between Serb forces and ethnic Albanian separatists, adding two of the children were taken to the hospital with serious injuries. Their ages were not immediately available.
More than eight years after the end of the war in Kosovo, parts of the countryside are still littered with unexploded ordnance and mines despite efforts to remove them.
Kosovo has been administered by the United Nations and NATO-led peacekeepers since June 1999, following the alliance's air war that halted the crackdown of Serb troops on independence-minded ethnic Albanians.
The companies involved in the implementation of the Nord Stream-2 project may deal with restrictive measures against them, a spokesman for the US Department of State said