In a retaliatory move, wireless chip giant Qualcomm is asking Chinese authorities to ban the sale and manufacture of iPhones in the country, Bloomberg reported Friday.

China, where most iPhones are assembled, accounted for nearly one-quarter of Apple’s sales in 2016. The iconic smartphone brings in almost two-thirds of Apple’s revenue.

Qualcomm’s suits, filed in a Beijing intellectual property court, claim patent infringement and seek injunctive relief. Company spokeswoman Christine Trimble said that “Apple employs technologies invented by Qualcomm without paying for them.”

The suits leverage three non-standard essential patents which cover power management and Force Touch technology that Apple uses in its touch screens (they probably mean 3D Touch). Those are, in Qualcomm’s words, a few examples of the “many Qualcomm technologies that Apple uses to improve its devices and increase its profits.”

The chip maker previously asked US regulators to ban the import of some iPhone models over purported infringement of its patents, considered essential to cellular communication.

Qualcomm and Apple first locked horns earlier in the year when the iPhone maker leveled an antitrust suit against Qualcomm, alleging unfair licensing practices. The chip giant charges a percentage of the price of each handset regardless of whether it includes its chip.

Critics say Qualcomm is making sales of its chips conditional on the purchase of a patent license while refusing to make its essential technology available to rival chip makers. The firm apparently charges high royalty rates unless phone vendors agree to buy its chips.

Apple cut off licensing payments to Qualcomm and asked its suppliers to follow suit. Qualcomm suggested Apple was looking for ways to reduce its costs amid slowing iPhone shipments.

The move forced Qualcomm to lower earnings forecasts because Apple payments accounted for about $2 billion per year in highly profitable revenue, according to analyst estimates.

Qualcomm’s CEO previously alluded to a possible out of court settlement. Given the latest legal maneuvering on both sides, any settlement is now in the realm of wishful thinking.