Worker protests at an iPhone manufacturing plant in India have caused up to $7 million in damages, Reuters reports. Workers at the plant, owned by the Taiwanese-based company Wistron, say they haven't been paid what they were promised and are demanding better working conditions.

The Times of India has several on-the-ground reports and dramatic video of the protests. The news outlet reports, "A majority of the nearly 2,000 employees, who were exiting the facility after completing their night-shift, went on a rampage destroying the company's furniture, assembly units and even attempted to set fire to vehicles."

The Times of India also has details on the salary workers were supposed to be getting, with the report quoting an employee as saying, "While an engineering graduate was promised Rs 21,000 ($286) per month, his/her salary had reduced to Rs 16,000 ($218) and, subsequently, to Rs 12,000 ($163) in the recent months. Non-engineering graduates' monthly salary had reduced to Rs 8,000 ($109). The salary amount being credited to our accounts have been reducing and it was frustrating to see this." Some workers claim to have gotten monthly salaries of as little as Rs 500 ($6.80).

Wistron is one of Apple's top suppliers, and Apple says it is investigating the company to see if Wistron violated Apple's supplier guidelines.

India is the world's second-largest smartphone market after China, but India is an extremely competitive, price-conscious market that Apple has struggled in, only capturing around 3 percent of the market. One way for Apple to lower prices in India is to build phones locally, allowing it to dodge Indian import fees that are especially high on goods made in China. The Wistron plant, naturally, makes Apple's cheapest phone, the iPhone SE.