A Serb politician admitted to masterminding the recent gun attack against Kosovo police earlier this week, according to a statement made by his lawyer.

The killing of a Kosovo police officer and the ensuing gun battle at a monastery in a village close to the Serbian border marked one of the gravest escalations in the former breakaway province in years.

Three Serb gunmen were killed in an hours-long firefight with Kosovo police after they ambushed a patrol near the village of Banjska and later barricaded themselves at an Orthodox monastery.

Milan Radoicic – the long-serving vice president of the Srpska Lista party – said he led the group of heavily armed gunmen into the area in northern Kosovo in response to alleged repression against Serbs by the Pristina government.

Radoicic insisted that he had acted alone and without the support or consent of the Serbian government.

"I did not inform anyone in the power structures of the Republic of Serbia, nor in the local political structures in northern Kosovo," wrote Radoicic in a letter read aloud by his attorney Goran Petronijevic at a press conference in Belgrade on Friday.

According to his letter, Radoicic said the killing of a Kosovo police officer in the ambush near the Serbian border was an "accident."

"The death of the policeman was accidental and was followed by a fierce confrontation in which our three comrades – the heroes – gave their lives for freedom and for the preservation of Kosovo," Radoicic wrote.

"We are not terrorists, we are the freedom fighters of our people," his letter stated, which included his resignation from Srpska Lista.

Earlier this week, Kosovo's interior minister accused Radoicic of masterminding Sunday's attack and released a video allegedly showing the suspect among a group of armed men at the Banjska monastery.

Serbian President Aleksandar Vucic said this week that Radoicic was in "central Serbia" and that authorities were prepared to question him.

Kosovo's government has accused Belgrade of backing the entire operation, with Prime Minister Albin Kurti writing on social media that the weapons and equipment used in Sunday's attack were "made by Serbian state-owned military arms producers."

Radoicic – who is currently under U.S. sanctions – has long been a major powerbroker among Serbs in Kosovo's restive north.

Earlier Friday, Kosovo police fanned out again across the north as they conducted an operation that saw the special units raid properties linked to Radoicic.

Kosovo, a former province of Serbia that broke away and declared independence in 2008 – a status Belgrade has refused to recognize – has long seen strained relations between its ethnic Albanian majority and its Serb minority population.