Updated

A U.S.-based rights group says China might be obscuring the number of dissidents it is targeting by charging them with public order offenses instead of political crimes.

The Dui Hua Foundation said Wednesday that it estimates the number of indictments in China for state security offenses such as subversion and separatism fell last year to the lowest level since 2007. Dui Hua is a San Francisco-based group that advocates for clemency for political prisoners.

But the group says authorities appear to be instead targeting more political dissidents with crimes of disturbing social order, such as illegal assembly.

Indictments for disturbing social order rose by 11,000 last year from 2012, according to statistics released by China's top prosecutors' office Monday. The office did not immediately respond to a request for comment.