An international advocacy group has filed a lawsuit against several major U.S. companies, on behalf of Congolese children who mine cobalt used in electronic devices.

According to CBS News, International Rights Advocates brought forth the complaint against Apple, Microsoft, Google, Dell and Tesla on Sunday. The lawsuit accuses the companies of "knowingly benefiting from and aiding and abetting the cruel and brutal use of young children in Democratic Republic of Congo to mine cobalt."

The children allegedly worked at mines owned by UK mining company Glencore, which sells cobalt to Umicore, a metal and mining trader, which then sells battery-grade cobalt to the companies mentioned in the lawsuit. The defendants are accused of being complicit given the knowledge that the cobalt used in their products is linked to child labor. 

Several children reportedly made less than $3 per day and died or got hurt from working in dangerous cobalt mines, which are allegedly part of the companies' unregulated supply chains. 

According to ABC News, the advocacy group said children as young as 6 years old "are not merely being forced to work full-time, extremely dangerous mining jobs at the expense of their educations and futures; they are being regularly maimed and killed by tunnel collapses and other known hazards common to cobalt mining."

The lawsuit, which includes more than a dozen anonymous plaintiffs, mentions a 15-year-old teenager who fell down a 20-foot shaft and "is now completely paralyzed from his chest down." 

Terry Collingsworth, executive director of International Rights Advocates, said: "this astounding cruelty and greed needs to stop."

"We will do everything possible to get justice quickly for the children we represent," Collingsworth said in a statement. "In my 35 years as a human rights lawyer, I’ve never seen such extreme abuse of innocent children on a large scale." 

There were about 40,000 children working in the DRC mines in 2012, according to a study by UNICEF. More than 60% of cobalt now comes from the DRC, with demand for the material tripling in the last five years as electronics companies strive to make cheap handheld devices, The Guardian reports. 

Apple released a statement to CNN, saying it remains "deeply committed to the responsible sourcing of materials that go into our products."

"Since 2016, we have published a full list of our identified cobalt refiners every year, 100% of which are participating in independent third-party audits," Apple said. "If a refiner is unable or unwilling to meet our standards, they will be removed from our supply chain. We've removed six cobalt refiners in 2019."

Dell also issued a statement, saying the company has "never knowingly sourced operations using any form of involuntary labor, fraudulent recruiting practices or child labor."

"We work with suppliers to manage their sourcing programs responsibly," Dell said. "Any supplier with reports of misconduct is investigated and, if misconduct is found, removed from our supply chain."

Google, whose parent company Alphabet is listed as a defendant, said: "Child labor and endangerment is unacceptable."

"Our Supplier Code of Conduct strictly prohibits this activity," the tech giant said. "We are committed to sourcing all materials ethically and eliminating child mining in global supply chains."

Microsoft told The Telegraph "If there is questionable behavior or possible violation by one of our suppliers, we investigate and take action."