Prosecutors began wrapping up the International Criminal Court's landmark first trial on Thursday by urging judges to convict a Congolese warlord of recruiting hundreds of child soldiers and sending them to fight and kill in his country's brutal conflict.

Deputy Prosecutor Fatou Bensouda told judges that evidence in the trial that began in January 2009 gave voice to children that militia leader Thomas Lubanga had "transformed into killers; those girls that Mr. Lubanga offered to his commanders as sexual slaves."

Bensouda said the armed wing of Lubanga's Union of Congolese Patriots political party trained hundreds of children in 20 camps scattered across the Ituri region of eastern Congo in 2002-2003.

"They were used to fight in conflicts. They were used to kill, rape and pillage," she added.

Actress Angelina Jolie, who is a goodwill ambassador for the U.N. High Commissioner for Refugees, was among dozens of people who watched proceedings from the court's public gallery. She made no comment to reporters.