Taiwanese smartphone firm HTC has fired a fresh salvo in its continuing war with Apple over patent infringement.
HTC has used patents it bought from Google last week to lodge a fresh complaint against Apple with the US International Trade Commission (ITC).
It has alleged that Apple's computers and mobile devices infringe patents involving wi-fi capability and processor communication technology.
This is the third complaint that HTC has filed against Apple.
"We are taking this action against Apple to protect our intellectual property, our industry partners, and most importantly our customers that use HTC phones," said Grace Lei, general counsel of HTC.
Apple v Android?HTC is not the only smartphone maker involved in a legal tussle with Apple.
Samsung Electronics, which makes the Galaxy series of smartphones and tablet PCs, has also been fighting a legal battle against Apple.
"Start Quote
End Quote Tim Charlton Charlton Media GroupIt is becoming an Apple versus Android war. Google is trying to fight a proxy war with Apple through its licensees such as HTC"
Apple has filed complaints against the South Korean manufacturer, accusing it of infringing its patents. It said that Samsung had copied the design and look of Apple's iPhone and iPad devices.
Samsung has counter-sued Apple, saying it infringed Samsung's wireless patents.
Both HTC and Samsung use Google's Android operating system in most of their smartphones.
Analysts said that HTC's latest legal action, which uses patents it acquired from Google, indicates that the tussle is becoming a much bigger issue than just a simple fight between two manufacturers.
"It is becoming an Apple versus Android war," Tim Charlton of Charlton Media Group told the BBC.
"Google is trying to fight a proxy war with Apple through its licensees such as HTC." he said.
Andrew Milroy of Frost & Sullivan added that tighter co-operation between HTC, Samsung and Google would create a strong rival to Apple.
"I see them being in a very strong position if they get together to take on Apple," he said. "Google plus Samsung plus HTC is a very big force to fight against."
Many frontsThe companies have been stepping up their legal action against each other this year.
And in the early salvos, Apple seems to have got the upper hand.
"We think competition is healthy, but competitors should create their own original technology, not steal ours," Carolyn Wu, a spokeswoman for Apple, told the BBC.
Last month, a court in the Netherlands banned Samsung from selling three models of its Galaxy smartphones in a number of European countries after Apple filed a claim for patent infringement.
Earlier this week, Samsung pulled out its new Galaxy Tab 7.7 from the IFA electronics fair in Berlin, one the world's largest electronics shows, after a court blocked sales of the product in Germany.
"Right now Apple is winning the patent war," Mr Charlton said.
'Weapon to compete'Analysts said the regularity with which these companies have been taking legal action against each other was also an indicator they may be using it as a competition tool.
"It seems it is being used as a weapon to compete, to slow down rival products from coming out in the market," Frost & Sullivan's Mr Milroy said.
Mr Milroy explained that the rapid growth in the smartphone and tablet PC sector had turned the segments from being a niche market to a mainstream one.
That, he said, had resulted in an increased push from various players for a bigger market share.
"I guess it will go on as long as the market is growing at this phenomenal rate," he said.
"Once the market slows down, we will see a return to conventional competitive techniques."