Vucic’s order was handed over to the chief of the Serbian army general staff, Serbian agency Tanjug reported citing the president’s office on Saturday.

The decision follows an incident in the southwestern part of the country, Kosovo special forces reportedly entered. Some 60 troops took positions near the dam on Gazivoda Lake, which hosts hydroelectric power station, according to local media.

Serbian Interior Minister Nebojsa Stefanovic said the police were also put on high alert following the Albanian “attack” in the north of Kosovo and Metohija and the “arrests of Serbs,” who did not commit any crime.

Kosovo dismissed the claims of occupying the area and said there were no arrests, according to the local deputy police commander, Besim Hoti, as cited by RTS. He added that the forces were at Gazivoda for a “single visit.”

The control over the lake and its facilities has been a matter of dispute between Belgrade and Pristina for years. Gazivoda is the major drinking water supplier for several municipalities of the region and a local power station also uses the water from it.

Self-proclaimed Kosovo unilaterally declared independence from Serbia in 2008 and the recognition of the region is matter of a major international dispute. Kosovo has been recognized by the US and a number of its allies, yet, a number of countries, including Spain, China and Russia opposed the controversial move. In fact, over half of the UN states did not support Kosovo’s independence.

UN Secretary General Antonio Guterres said on Friday that “Kosovo is not a state” for the international organization.