Before the Kosovan police begin their patrol of the border with Serbia, they load up the car with weaponry: AK-47s are strapped to the back of car seats, handguns dropped in the footwells, and drones and bulletproof vests stuffed in the Land Rover’s boot.

This is now standard protocol on one of the most volatile frontiers on the European continent.

When people ask Venton Elshani, the deputy police commander of North Kosovo, what the situation is like he simply shows them the preparations he takes for patrol. “You see the weapons?” he said, before taking The Telegraph out to the border, “these are for police officers to carry. The situation is not good.”

Since Kosovo won independence from Yugoslavia in a war that ended in 1999, it has played host to a small community of ethnic Serbs in the northern border region. Tensions with the ethnic Albanian majority have surged lately. Alexander Vucic, Serbia’s president, has hinted at an invasion – nationalists urge him to act to “protect” the Serbs forced to live under Kosovan rule.

Fears of a fresh war spiked in 2023 when a group of Serbian gunmen stormed across the border into the northern village of Banjska and barricaded themselves in its monastery. Three of a suspected 30 militants were killed in a shoot-out. One of Commander Elshani’s men lost his life in the cross-fire.

Since that day, the officer and his team have conducted daily patrols in the Serbian-dominated border region, hunting for illegal roads into Serbia of the kind used by the gunmen in their assault. 

“We know these roads better than anyone,” Commander Elshani told The Telegraph as the patrol wended its way through the mountains. 

“The Serbs can’t make a road we won’t find.” 

At the last count police identified 65 illegal roads, all of which have been blocked with large ditches cut through the concrete.

A further 10 roads are kept under constant surveillance, mainly via drones.

Having a constant presence in the Serb-majority region sends a message to Belgrade that Kosovo is protecting its borders, Commander Elshani said.

“Banjska changed the game, put the game into another level because of the deaths,” he said.

“When the blood is shed, then it’s a problem.”

Analysts warn that Kremlin propaganda is fuelling unrest in the north in a nation where 93 per cent are Albanian and 4 per cent are Serb. The majority of Serbs in Kosovo still regard Belgrade, which has never recognised Kosovo’s independence, as their government.

After the siege, authorities uncovered a huge arms cache the attackers had stashed in disused buildings around the northern villages. Only a few weeks ago they discovered five more rocket launchers, a sign of the scale of the planned attack.

In an interview with The Telegraph Albin Kurti, Kosovo’s prime minister, warned that Aleksander Vucic, the president of Serbia, planned to invade. He said Serbia had built up forward operating bases around the border in a “horseshoe shape” to  “defend Belgrade and attack Kosovo”. 

Distraction from war in Ukraine

Based on President Vucic’s own words, Mr Kurti believes the Serbian president is biding his time for an opportunity to invade.

President Vucic’s friendship with Vladimir Putin is well known, and Mr Kurti believes it is in the Russian leader’s interest for Serbia to invade Kosovo as it would distract from his war in Ukraine.

Back down the mountain, at the Mitrovica Bridge which straddles the River Ibar, Serbia’s red, white and blue flag flutters everywhere. Once this bridge was a “hot spot” – an informal division between Kosovo’s northern border region and the ethnic Albanian south. Things appear peaceful as pedestrians walk freely between the two sides.

But there is an undercurrent of tension. Some ethnic-Serbian residents from the north view anyone who crosses into the south as a traitor betraying the unhealed wounds from the bloodshed of the 1990s.

Cars are still not permitted to drive over the bridge, prevented by a blockade and the 24/7 presence of two police Land Rovers, one parked facing south and the other north.

Police said these precautions were essential to maintain stability in the area.

Rumours swirl that Putin has recruited Serbians to fight in his army against Ukraine and as The Telegraph travelled around the north, the solidarity with Russia was omnipresent.

The letter “Z” had been graffitied onto the sides of shop, cafes and local homes.

Prime Minister Kurti said: “This is the pool from where they [Russia] will recruit future Wagner wannabe paramilitaries for Ukraine and the Balkans.”

On one road sign, someone had stencilled the words “F--- You Nato”, a warning to the bloc’s KFOR-peacekeeping presence, which has been stationed in Kosovo since 1999.

Like the police they conduct patrols, keeping an eye on what they refer to as the administrative border line, a 237-mile stretch of land dividing Kosovo and Serbia.

First Lieutenant Caldwell of Georgia’s National Guard, which makes up America’s contribution to KFOR, said their task was to detect anyone intending to pursue hostile activity.

He stressed the importance of “cutting up” illegal roads to stop smugglers crossing into Kosovo. He said more were being built whenever possible. For Elshani, his men are in training for an attack.

“It’s not a surprise Vucic wants to invade,” he said. “They can shoot us but they can’t scare us.”