(Reuters) - Apple Inc on Wednesday filed a countersuit against Qualcomm Inc, alleging that Qualcomm’s Snapdragon mobile phone chips that power a wide variety of Android-based devices infringe on Apple’s patents, the latest development in a long-running dispute.

Qualcomm in July accused Apple of infringing several patents related to helping mobile phones get better battery life.

Apple has denied the claims that it violated Qualcomm’s battery life patents and alleged that Qualcomm’s patents were invalid, a common move in such cases.

But on Wednesday, in a filing in U.S. District Court in San Diego, Apple revised its answer to Qualcomm’s complaint with accusations of its own. Apple alleges it owns at least eight battery life patents that Qualcomm has violated.

The Apple patents involve ensuring each part of a phone’s processor draws only the minimum power needed, turning off parts of the processor when they are not needed and making sleep and wake functions work better.

In its filing, Apple alleges that Qualcomm’s Snapdragon 800 and 820 processors, which power phones from Samsung Electronics Co Ltd and Alphabet Inc’s Google’s Pixel phones, infringe on those patents. Samsung and Google are not named in Apple’s counterclaims.

“Apple began seeking those patents years before Qualcomm began seeking the patents it asserts against Apple in this case,” the company wrote in its complaint.

Apple said it is seeking unspecified damages from San Diego-based Qualcomm.

Qualcomm filed its patent infringement lawsuit at the same time it filed a complaint with the U.S. International Trade Commission seeking to ban the import of Apple iPhones that use competing Intel Corp chips because of the alleged patent violations.

The dispute between Apple and Qualcomm over patents is part of a wide-ranging legal war between the two companies.

In January, Apple sued Qualcomm for nearly $1 billion in patent royalty rebates that Qualcomm allegedly withheld from Apple. In a related suit, Qualcomm sued the contract manufacturers that make Apple’s phones, but Apple joined in to defend them.

Separately, Qualcomm is facing a lawsuit from the U.S. Federal Trade Commission over many of the same pricing practices Apple names in its complaints.

(This version of the story was refiled to add the missing word “of” in the headline)