Apple has countersued Creative Technology, alleging the company infringes four patents it holds for digital music players.
The news follows Creative's move to sue Apple earlier this week, alleging its rights to enforce a patent it holds on user interfaces, which it calls the "Zen Patent".
Apple filed its suit in a Wisconsin District Court on May 15, the same day Creative filed its own against Apple, reports the Herald Tribune.
A seemingly surprised spokesman for Creative told the Herald Tribune: "Creative proactively held discussions with Apple in our efforts to explore amicable solutions. At no time during these discussions or at any other time did Apple mention to us the patents it raised in its lawsuit."