Underage workers used: Foxconn

Foxconn said it would work with local government to bar the schools involved in the Yantai case from the intern programme unless shown to be compliant with labour law and company policy.

However, we recognize that full responsibility for these violations rests with our company and we have apologized to each of the students for our role in this action, the firm said.

Foxconn and Apple have been forced to improve working conditions at Chinese factories that make most of the world's iPads and iPhones after a series of well-publicised suicides in 2010 and reports of labour abuses, such as excessive overtime, threw a spotlight on conditions inside the plants.

Last month, a riot broke out at a Foxconn plant assembling iPhones in the northern city of Taiyuan over living conditions inside Foxconn's on-site dormitories for migrant workers.

In response to the scrutiny, Foxconn plans to cut overtime to less than nine hours a week from the current 20.

It defended its intern programme on Tuesday, saying they made up only 2.7 percent of its workforce in China. Internships could be long-term or short-term, carried out in cooperation with vocational schools and other educational institutions.