A spokesman for the NATO-led Kosovo Force (KFOR) said two of the NATO personnel -- a German commander and a soldier -- were shot by Serbs who fired small arms in the November 28 violence. The other injured soldiers are said to include Germans and Austrians.
Serbian reports said dozens of Serbians have sought medical aid after being hurt in the clashes.
Kosovo President Atifete Jahjaga has condemned the violence, according to RFE/RL's Balkan Service, as have EU officials.
In Belgrade, Serbian President Boris Tadic, whose country does not recognize Kosovo's 2008 declaration of sovereignty, pleaded for calm and nonviolence.
KFOR spokesman Uwe Nowicki said NATO soldiers had used pepper spray, tear gas, rubber bullets, and water cannon to disperse Serbs who were trying to prevent NATO from removing a roadblock near the town of Zubin Potok.
Nowicki accused Serbs of using explosive devices and Molotov cocktails to attack the NATO-led troops.
"The protesters could not be called as peaceful demonstrators at all, but as violent and criminal,” said Nowicki. “Up to now, KFOR only used pepper spray, tear gas, rubber bullets, and water cannon. However, in life-threatening situations like this, KFOR soldiers will respond as of now with all proportionate and appropriate means."
Speaking in Pristina, Nicholas Hawton, a spokesman for the European Union law and justice mission in Kosovo (EULEX), denounced the violence.
"EULEX absolutely condemns violence of this kind against KFOR or against any international institutions," he said. "KFOR and EULEX are in northern Kosovo to try and improve and increase the rule of law and this violence is condemned and our thoughts are obviously with the two KFOR soldiers who have been injured this morning."
President Jahjaga repeated Pristina's call for the "criminals who attacked [the] KFOR soldiers" to face justice and Belgrade to "end its involvement and stop supporting criminal structures" in northern Kosovo, where many ethnic Serbs live, according to RFE/RL's Balkan Service.
Serbia President Tadic urged both sides to "immediately calm down the situation and ensure full freedom of movement exclusively through dialogue and without using violence."
Minority ethnic Serbs in northern Kosovo, backed by the Serbian government in Belgrade, continue to reject the three-year-old declaration of independence by Kosovo's ethnic Albanian leadership.
Kosovo independence has been recognized by some 85 countries, including the United States and most members of the European Union.
based on RFE/RL Balkan Service and agency reports