Kosovo’s prime minister welcomed the decision, saying Serbia’s attempting to destabilise its former province with the help of ally Russia.

Kosovo’s prime minister on Friday welcomed a NATO decision to bolster its troops in the volatile Balkan region, saying last weekend’s shootout that left four people dead illustrates Serbia’s attempts to destabilise its former province with the help of ally Russia.

“These people want to turn back time,” Prime Minister Albin Kurti told The Associated Press. “They are in search of a time machine. They want to turn the clock back by 30 years. But that is not going to happen.”

NATO said in a statement that it had “authorised additional forces to address the current situation” but did not immediately specify how many or from which countries.

A later statement from the United Kingdom’s Ministry of Defence said it had transferred command of a battalion of troops to the alliance.

US Secretary of State Antony Blinken spoke with Serbian President Aleksandar Vucic on Friday and stressed the importance of de-escalating tensions with Kosovo after recent violence and the death of a Kosovo police officer, the Department of State said.

“The secretary underscored that those responsible for the attacks who are now in Serbia must be held accountable,” it said in a statement.

Kosovo police on Friday raided several locations in a Serb-dominated area of the country’s north, where weekend violence left one Kosovo police officer and three Serb fighters dead and further strained relations between Serbia and its former province.

Kosovo police said in a statement that they were conducting searches at five locations in three municipalities. The operation was connected to a Sunday shootout between Serb fighters and police officers in the village of Banjska in northern Kosovo.

The confrontation was one of the worst since Kosovo declared independence from Serbia in 2008, with Belgrade refusing to recognise the split. NATO, which leads the KFOR peacekeeping force in Kosovo, announced Friday that it would strengthen its presence.

“We need NATO because the border with Serbia is very long and the Serbian army has been recently strengthening its capacities and they have a lot of military equipment from both the Russian Federation and China,” Kurti said.

Kosovo, which declared independence from Serbia in 2008 after an armed uprising and 1999 NATO intervention, has accused Serbia of arming and supporting the Serb fighters.

Serbia, which has not recognised its former province’s independence, has accused Kosovo of precipitating violence by mistreating ethnic Serb residents. Serbia and Kosovo’s main Serb political group have proclaimed public mourning for the Serbs killed in the battle.

The UK’s Ministry of Defence said it had transferred command of the 1st Battalion of the Princess of Wales’s Royal Regiment – a reserve force for NATO’s Kosovo Force (KFOR) – to NATO to provide support if required.

It said the battalion had recently arrived in the region for a long-planned training exercise.