Samsung Electronics Co. said Friday it had filed lawsuits against Apple Inc. in South Korea, Japan and Germany, a week after its rival sued it over allegedly violating patents and trademarks of the iPhone and iPad.

Samsung said it filed a suit Thursday in the Seoul Central District Court alleging infringements of up to five patents by Apple. Separate suits were filed in Tokyo citing two patent infringements and in the German city of Mannheim citing three. " Samsung is responding actively to the legal action taken against us in order to protect our intellectual property and to ensure our continued innovation and growth in the mobile communications business," the company said in a statement.

Apple's lawsuit, filed last Friday in San Francisco, claims Samsung allegedly copied the design of its iPhone and iPad. Samsung said at the time it had conducted its own research and development and would contest the allegations.