Apple supplier Foxconn Technology Group said hat it found interns as young as 14 working at one of its facilities in Yantai, northeastern China.

The confirmation from Foxconn, the world's largest electronics manufacturer, comes one day after an advocacy group claimed that underage workers were employed at Yantai over the summer.

On Monday, Oct. 15, advocacy group China Labor Watch issued a statement claiming that a "small number" of interns were sent by schools to work at Foxconn's Yantai facility over the summer. A company investigation found that interns ranging in age from 14 to 16 had worked at the facility for roughly three weeks, Foxconn told Bloomberg News in an e-mailed statement on Tuesday, Oct. 16.

"Any Foxconn employee found, through our investigation, to be responsible for these violations will have their employment immediately terminated," further reads Foxconn's e-mail, according to Bloomberg.

"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 minimum working age in China is 16. Foxconn said the underage interns it found at the Yantai facility were sent back to their schools. Back in August, the company faced a complaint that vocational students were forced by their schools to work at Foxconn factories in China. The company argued that the students were free to leave at any time.

This is not the first time Foxconn has been criticized over working conditions at its factories. The underage interns add to multiple labor issues including suicides, riots, and strikes at the company's facilities in China over the past three years.

Earlier this month, on Oct. 5, one of the company's factories in Zhengzhou, China, lost two shifts after workers became frustrated with the stricter policies regarding scratches and damage on the casings of the new iPhone 5. Meanwhile, last month Foxconn halted production at a plant in northern China's Taiyuan city due to a brawl involving as many as 2,000 workers. Back in 2010, at least 10 Foxconn employees committed suicide.

Foxconn employs more than one million workers in the country. Following a firestorm of controversy and severe criticism over working conditions, Apple Chief Executive Officer Tim Cook brought his company into the Washington-based Fair Labor Association in January, allowing outside observers to inspect Foxconn's plants.

According to China Labor Watch, the schools which sent the underage interns to the Yantai factory should take primary responsibility, but Foxconn is also culpable for not confirming their ages before allowing them to work there. Foxconn said it was investigating with schools to determine how the interns were sent to its factory.