A Swiss-based think tank says armed conflicts kill or injure thousands of people a year, but it is not always clear whether there is a potential for investigating and prosecuting war crimes.

The Geneva Academy of International Humanitarian Law and Human Rights says that in 2012 there were 38 armed conflicts in 24 nations and territories, including Syria's civil war, but little justice because of the lack of clarity.

Its "War Report" published Tuesday says Turkey, Mexico and Thailand do not recognize armed conflicts on their territory, but Britain and the U.S. prosecuted troops for war crimes in Afghanistan.

Andrew Clapham, a law professor at the institute, says "it is not always clear when a situation is an armed conflict, and hence when war crimes can be prosecuted."