A former Kosovo rebel commander compared a war crimes tribunal to Nazi Germany’s secret police as they began their first trial in The Hague yesterday.

Salih Mustafa is accused of murder and torture in a makeshift Kosovo Liberation Army (KLA) detention center during the 1998-1999 war of independence with Serbia.

“I am not guilty of any of the charges brought before me by this Gestapo office,” said Mustafa, 49, as his trial began before specialized chambers in Kosovo.

Dressed in a black hooded top and jogging pants, Mustafa swayed in his chair and repeatedly tapped a pen on his fingers as he listened to the trial opening on headphones.

Mustafa, who was arrested last year while working as an adviser to the Kosovo Ministry of Defense, is the first suspect to stand trial by the court, established in 2015 to investigate atrocities committed by the separatist KLA .

Prosecutors said Mustafa and his men “brutalized and tortured” other Kosovar Albanians whom they accused of collaborating with Serbs in Zllash, a village east of the capital Pristina.

“They were not enemies of Kosovo, they were not spies,” Senior Prosecutor Jack Smith told the court in his opening statement.

“Their only crime was to have political views different from those of the KLA and its senior leaders.

The prosecutor said the hearing was an “important step” for the court, which took six years to bring anyone to justice and faced problems with witness intimidation.

Mustafa faces charges of murder, torture, cruel treatment and arbitrary detention involving at least six detainees.

According to the indictment, detainees were held in a locked stable and subjected to “beatings with various instruments, fires and the administration of electric shocks”. Some were urinated in front of other detainees.

Mustafa allegedly personally hit and slapped an inmate with a baseball bat, punched and kicked another.

Smith said the prisoners were being held in “inhumane” conditions, Mustafa having personally participated in the beatings.

A young man died after being “repeatedly beaten and tortured”.

Mustafa is accused of being jointly responsible for the murder either knowing that the crime was being committed or knowing that the victim was in danger of being killed.

The trial will hear 16 witnesses, including former detainees, in September and October.

The Kosovo war, which claimed 13,000 lives, ended when the forces of Serbian President Slobodan Milosevic withdrew after an 11-week NATO bombing campaign.