BELGRADE, Serbia 

Kosovo said Sunday it has evidence that Serbia was trying to annex its northern region and that the attackers had been preparing for this a long time at military bases.

''This terrorist organization had only one purpose: the annexation of the north of the Republic of Kosovo,” said Interior Minister Xhelal Svecla.

“In order to realize this goal, Serbian institutions organized its military, logistic and financial capacities," Svecla said during a press conference at a police camp in the northern city of Mitrovica.

According to Svecla, Serbian President Aleksandar Vucic, Defense Minister Milos Vucevic and Army Chief of Staff Milan Mojsilovic were directly engaged in the attempt.

''The Serbian president has sought to deny the fact that the state he leads was involved in the planning and execution of the Sept. 24 attack, but the documents we published earlier and the footage we will publish today are clear evidence of the engagement of military and state structures in this organization,'' he said.

On Sept. 24, a clash broke out in the village of Banjska in northern Kosovo near the Serbian border when a group of armed Serbs blocked a bridge with two trucks. A shootout erupted after the group opened fire on police, leaving one police officer dead and another injured.

A large number of security forces were dispatched to the region, and the Brnjak border crossing between Kosovo and Serbia was closed.

The area has been the scene of unrest since April, when local ethnic Serbs boycotted elections in northern Kosovo, followed by protests against the election of ethnic Albanian mayors.

Albanians are by far the largest ethnic group in Kosovo, followed by Serbs, with about half living in the country's north.

Amid the unrest over the elections, NATO peacekeepers were deployed, including a group of extra Turkish reinforcements.

The last week has seen a “large Serbian military deployment along the border with Kosovo," according to the US National Security Council, whose spokesman called the deployment “a very destabilizing development.”

Kosovo on Saturday called on Serbia to pull back its troops.

NATO Secretary-General Jens Stoltenberg wrote Friday on X that “NATO Allies met today & expressed deep concern about tensions in northern Kosovo.”

Vucic later denied that Serbia was engaging in a military build-up along the border with Kosovo.

“A campaign of lies…has been launched against our Serbia,” he said in a video posted on Instagram on Sunday.

“They have lied a lot about the presence of our military forces…In fact, they are bothered that Serbia has what they describe as sophisticated weapons,” he added.

Kosovo declared independence from Serbia in 2008 and gained recognition from many countries, including Türkiye. But Belgrade has never recognized Kosovo and claims that its territory is still part of Serbia.