A total of 5.4 million speakers of an Indian language, or 79.3 percent of that group, lived in poverty in 2010, up by 100,000 from the figure in 2008, the National Social Development Policy Evaluation Council, or Coneval, said.

Of these 5.4 million Indians, some 2.7 million "were (living) in extreme poverty," Coneval said in a statement.

About 5.3 million speakers of an Indian language, or 75.9 percent of that group, lived in poverty in 2008, the independent government agency said.

Coneval's estimates take into account only speakers of an Indian language, a group whose numbers are estimated at 6.8 million.

Some 15.7 million people in Mexico, according to the 2010 National Population and Housing Census, identify themselves as Indians.

Mexico has more than 60 Indian groups, with the languages most spoken being Nahuatl (23 percent), Maya (11.5 percent), Tzeltal (7 percent), Tzotzil (6.9 percent) and Zapotec (6.4 percent), the National Statistics Institute says.

The Mexican Constitution defines Indians as those descended from the peoples who inhabited Mexico's territory when the period of European colonization began and have preserved their social, economic, cultural and political institutions, or part of them.

An awareness of Indian identity is a fundamental criteria for being identified as a member of one of these groups, the constitution says.

The Coneval report was released to mark International Day of the World's Indigenous People, which is being celebrated on Tuesday.