The ongoing legal battle between Apple and Nokia escalated again over the weekend as Apple asked regulators to block imports of Nokia phones into the US due to alleged patent infringements. Apple made its request in a complaint filed with the US International Trade Commission (ITC), reports CNet News. The filing was Apple’s response to Nokia’s earlier complaint to the ITC accusing the iPhone-maker of infringing Nokia patents in “virtually all of its mobile phones, portable music players, and computers,” and the latest in a tit-for-tat legal exchange between the two vendors. Responding to Apple’s latest move, Nokia spokesman Mark Durrant told Bloomberg that “Nokia will study the complaint when it is received and continue to defend itself vigorously,” and repeated Nokia’s earlier claim that Apple has “failed to agree to appropriate terms for using Nokia technology and has been seeking a free ride on Nokia’s innovation since it shipped the first iPhone in 2007.” Apple has not officially commented on its most recent filing.

According to a Reuters report, the ITC can ban selling products in the US – a market crucial for Apple, but accounting for only a fraction of sales at Nokia. “The fact that two such prominent companies have now filed complaints will likely mean the ITC will seek to deal with this as a matter of urgency,” said CCS Insight’s Ben Wood. Analysts agree that it could take years to solve the legal battle. “This dispute is still in its infancy,” said Steven Nathasingh, chief executive of US research firm Vaxa. “I don’t think Nokia is finished with evaluating the infringements by Apple, it might be just the surface.”