Serbia has reiterated a threat to intervene militarily in its former province of Kosovo if Nato-led peacekeepers there fail to protect minority Serbs from what Belgrade called the terrorist threat of Kosovo’s ethnic Albanian authorities.

In a brief televised address, the Serbian army chief-of-staff, General Milan Mojsilovic, said Kosovo Serbs can no longer “tolerate the terror” of the Kosovo government, and that Serbia’s military stands ready to fulfil its tasks “in accordance” with the Serbian constitution and any orders from President Aleksandar Vucic.

Serbia has put its troops on the border with Kosovo on the highest state of alert amid a series of recent clashes between Kosovo Serbs on one side and Kosovo police and Nato-led peacekeepers, known as KFOR, on the other.

In recent weeks, Nato has sent in reinforcements amid fears of an open clash between ethnic Albanians and Serbs.

Serbia’s armed intervention in Kosovo would mean a direct clash with some 4,000 Nato troops currently stationed there.

Serbia and its former province of Kosovo have been at odds for decades. Their 1998-99 war left more than 10,000 people dead, mostly Kosovo Albanians. Belgrade has refused to recognise Kosovo’s 2008 declaration of independence.

Tensions flared anew last month after Kosovo police seized local municipality buildings in northern Kosovo, where Serbs represent a majority, to install ethnic Albanian mayors who were elected in a local election that Serbs overwhelmingly boycotted.

The latest flare-up focused on Kosovo police arresting at least eight Serbs who are suspected of taking part in last month’s violent clashes with the Nato troops and Kosovo police, leaving dozens of injured on all sides.

In his brief address to the nation on Friday, the Serbian army chief-of-staff said that Kosovo Serbs can no longer “tolerate the terror of the regime of” Kosovo Prime Minister Albin Kurti.

“According to the facts, I informed the commander of KFOR that we demand urgent measures to protect the Serbian people,” Gen Mojsilovic said. “This is our request to KFOR and other international organisations.”

In their meeting in Brussels on Thursday, the leaders of Serbia and Kosovo made no breakthrough in EU-hosted emergency talks amid fears of a return to open conflict.

The EU’s foreign policy chief, Josep Borrell, described the soaring ethnic tensions in northern Kosovo as alarming.

“Despite yesterday’s crisis meeting, escalation continues (and) is becoming dangerous,” he tweeted on Friday. “We will not tolerate it.”

Nato secretary-general Jens Stoltenberg on Thursday vowed that the alliance’s peacekeepers “will continue to act impartially” and increase its presence to ensure environment and freedom of movement for all communities in Kosovo.

Both Serbia and Kosovo are seeking EU membership, and need to normalise their relations to do so.

There are fears that Serbia’s ally Russia could inflame another armed conflict in central Europe to divert at least part of the international focus from Moscow’s aggression in Ukraine.