Updated

A German NATO officer and a soldier were shot and wounded in a clash with Serb protesters in northern Kosovo on Monday after the military alliance's troops used heavy machinery to remove trucks and buses blocking a main road in the tense region, an official said.

The shooting near the town of Zubin Potok, some 40 miles northwest of Pristina come after months of tensions, following a decision by Kosovo's authorities to extend their authority in the areas under de-facto Serb rule.

For months Serbs have used soil, rock and concrete barriers to block any such moves. NATO has threatened to remove them because it cut off land supply to a military base in the north.

German and Austrian peacekeepers involved in the Monday operation fired rubber bullets and tear gas and used water canons and pepper spray to disperse the crowd of Serb protesters trying to stop the soldiers from removing the roadblock.

"The commander of the battalion was shot and another soldier was also wounded," said NATO spokesman, Lt. Col. Uwe Nowitzky.

In Berlin, a German military spokesman Lt. Col. Manfred Baumgartner told The Associated Press that the wounded officer and the soldier serve in the Bundeswehr. He said they were shot from the crowd of Serb protesters.

The two were sent at the U.S. military base in eastern Kosovo, Camp Bondsteel, for treatment, NATO said.

At least two injured Serb demonstrators were carried by medical workers to a nearby hospital, an AP reporter at the scene said. Serb media said dozens of Serb demonstrators sought medical help.

NATO said its soldiers are now under instructions to fire live ammunition if they come under attack.

On Tuesday more than 20 Portuguese and Hungarian soldiers were injured in a similar operation, one of them seriously.

Tensions in Kosovo's north rose over the summer when Kosovo authorities ordered special police units to set up customs on two border crossings with Serbia. Serbs responded by setting one of them on fire and blocking roads.

Many Serbs that live in the north say there should be no border with Serbia because they consider Kosovo to be part of Serbia, while ethnic Albanians want the border to support its 2008 declaration of independence from Serbia.

Kosovo's declaration of independence in 2008 has been recognized by 85 countries including the United States and most members of the European Union. But, many other nations still consider Kosovo's political status to be unresolved and want to see the two sides come to an agreement on resolving their dispute. Serbia does not recognize the new state.

The EU is in charge of technical talks between Kosovo and Serbia that seeks to soften the divide, but no tangible progress has been made so far.

The two delegations are expected to meet again in Brussels on Wednesday.