Nokia seems to have been determined to keep Apple locked in a legal battle, as the giant mobile phones manufacturer slapped the iPhone maker with another lawsuit alleging patent violations. The two leaders of the smartphone market are now tied in one of the fiercest legal battles ever.

On December 29, Nokia had filed the case at a Delaware court and the lawsuit seeks damages for Apple's alleged infringement of as many as 7 of Nokia's patents. The violation, the court documents say, can be seen in many of Apple's products.

The court case coincided with a claim that Nokia had filed with the U. S. International Trade Commission about the same patents. Nokia says that Apple has infringed the rights in virtually "all of its mobile phones, portable music players, and computers".

The court case is needed to ask for damages as the ITC does not deal with financial compensation.

Last year, both Apple and Nokia had filed patent infringement lawsuits against each other, and since then, both the firms have been locked in a heated legal battle.