SARAJEVO (Reuters) - Bosnia’s war crimes prosecutor on Friday indicted Milan Lukic, the Bosnian Serb paramilitary leader given a life sentence by a U.N. war crimes tribunal, for taking part in the kidnapping and killing of 20 people during the Bosnian war.

FILE PHOTO: Bosnian Serb Milan Lukic attends the appeals verdict in his trial at the International Criminal Tribunal for former Yugoslavia in The Hague December 4, 2012. REUTERS/Michael Kooren/File Photo

The International Criminal Tribunal for the Former Yugoslavia (ICTY) in The Hague convicted Lukic in 2009 of war crimes committed during the break-up of Yugoslavia in the 1990s and his life sentence was upheld by an appeals court in 2012.

The Bosnian prosecutor issued the indictment for a crime that wasn’t covered by the ICTY case after interrogating Lukic in Estonia, where he is serving his life sentence.

Lukic, 52, led a paramilitary group called the White Eagles or Avengers who seized, tortured and executed 20 people, mainly Muslims, from a train passing through Bosnia en route to the Montenegrin port of Bar from Serbia, the prosecutor’s office said in a statement.

The indictment now goes to Bosnia’s state court for confirmation. It was not clear what would happen if the charges were confirmed since Lukic has been jailed for life by the ICTY.

“The court will decide. The court first needs to confirm the indictment,” a spokesman for the prosecutor’s office said.

Convicts sentenced to life by the ICTY can request to be released after serving 30 years.

According to the prosecutor’s statement, Lukic’s group stopped the train, seized the victims, took them to a school in eastern Bosnia where they were beaten, tortured and robbed, and then took them to a place where Lukic took part in their murder.

“The defendant is accused of personally taking part in planning and ... kidnapping of civilians and their murder on the bank of the Drina River on Feb. 27, 1993,” the prosecutor’s office said, adding that Lukic had been charged with war crimes against the civilian population.

The victims were thrown into the Drina River. The remains of only four people have been found until now, it said.

Lukic is most notorious for barricading 70 Muslim men, women and children in a house in the eastern town of Visegrad in 1992 before setting it on fire, in what became known as the Pionirska Street massacre. He shot at people trying to escape.

Fifteen members of Lukic’s group were arrested in Bosnia and Serbia in 2014 and all are being tried at courts in Sarajevo and Belgrade.