Computer giant Apple is using suppliers that break China's labor laws and provide poor working conditions.

At least 11 children were found working last year in three factories, believed to be on the Chinese mainland, that assemble Apple's iPods, iPhones and Mac computers.

Some suppliers were making staff members work more than 60 hours weekly and improperly disposing of hazardous waste, according to the United States-based company's annual supplier report released on its Website.

Apple has supplier facilities elsewhere, including Taiwan, Singapore and Malaysia, but most of its products are assembled on the mainland.

"Apple required each facility to develop and institute appropriate management systems such as more thorough ID checks and verification procedures to prevent the future employment of underage workers," the company said in its Supplier Responsibility 2010 Progress Report.

Apple China yesterday declined to comment.

The report said Apple found three facilities that hired 11 workers under the minimum legal age of 16.

In the report, Apple admitted at least 55 of the 102 plants that produce its goods were ignoring a company edict that staff must not work more than 60 hours a week. Under Chinese labor laws, workers must not put in more than 49 hours weekly.

Only 65 percent of the factories were paying staff the correct wages and benefits.

Apple found 24 plants where workers were not even paid China's minimum wage of about 800 yuan (US$117) a month, the report said.

It was not the first time that Apple's suppliers, which operated 102 facilities with 133,000 workers in 2009, have received negative publicity.

It was reported last week that dozens of workers at a Suzhou factory, which manufactures products for Apple and Nokia, had been poisoned by n-hexane, a toxic chemical that can cause muscular degeneration and blurred vision.

Last year, an employee at Taiwan-based Foxconn, one of Apple's biggest suppliers, committed suicide after being accused of stealing a prototype of a new-model iPhone.