Serbia placed its armed forces on "the highest level" of alert, Defense Minister Milos Vucevic said late Monday, after a shooting incident in northern Kosovo.

Hours later, protesting Serbs in the city of Mitrovica erected new barricades.

Serbia and Kosovo have been at loggerheads once again after Kosovo moved to ban Serbian license plates last month. Pristina ultimately backed down, but the decision led to protests in the north of Kosovo, which has an ethnic Serb majority.

The defense minister said that President Aleksandar Vucic "ordered the Serbian army to be on the highest level of combat readiness, that is to the level of the use of armed force."

This included boosting the number of special armed forces personnel from 1,500 to 5,000.

The Serbian army has been put on heightened alert multiple times in recent years, including in November when drones allegedly entered Serbian airspace from Kosovo.

Hours later after the announcement, protesting Serbs in the city of Mitrovica erected new barricades. Since December 10, Serbs in northern Kosovo have put up multiple roadblocks, paralyzing two border crossings.

"Kosovo cannot engage in dialogue with criminal gangs and freedom of movement should be restored. There should not be barricades on any road," Kosovo's government said in a statement on Monday.

Police under military command

Also on Friday, Serbia's Interior Minister Bratislav Gasic said he "ordered the full combat readiness" of police and other security units and that they be placed under the command of the army chief of staff.

He said he acted on the president's order that "all measures be taken to protect the Serbian people in Kosovo."

Serbs account for around 120,000 people in Kosovo, which has a total population of 1.8 million people.

Predominately-Albanian Kosovo declared independence from Serbia in 2008, but Belgrade does not recognize this.

Kosovo's security council met on Monday and blamed Serbia for the latest breakdown in relations.

It accused Belgrade of "acting with all available means against the constitutional order of the Republic of Kosovo."

zc/wd (AFP, AP)