Although the famously secretive panel doesn't reveal who has been nominated, those people with nomination rights typically announce their picks. Geir Lundestand, the Norwegian Nobel Committee's nonvoting secretary, told the AP that this year's nominations include repeat nominees as well as others who aren't as well known to the public.
A nomination doedn't indicate a candidate's chances for winning. The Oslo-based Nobel Committee sends out thousands of letters to qualified individuals -- including members of international courts, university professors and board members of organizations that have been awarded the Peace Prize -- seeking nominations each year, the full list of which can't be revealed until 50 years after the nomination, according to the committee's website.
Others believed to have been nominated include former German chancellor Helmut Kohl, Russian human-rights activist Svetlana Gannushkina and Gene Sharp, an American scholar and nonviolence advocate who has reportedly been cited an inspiration for the Arab Spring and similar protests.
Manning, 24, has been charged with the biggest security breach in U.S. history after he allegedly provided classified material to the website WikiLeaks.
The Army intelligence analyst was held in solitary confinement for almost a year beginning in July 2010 after he had been accused of instigating the leak, which is said to have included hundreds of thousands of U.S. diplomatic cables as well as a July 2007 video of a Baghdad airstrike. The video, under the title Collateral Murder, shows a U.S. Apache helicopter opening fire on a dozen civilians, including two reporters from the Reuters news service.
Manning was found fit to face court-marial proceedings in April 2011 and is being tried in a military court, where he faces life imprisonment if convicted. His trial has attracted international attention and inspired the formation of several grass-roots support groups.