Nokia, the world's top cellphone maker by volume, has filed 13 new patent infringement suits in Europe against United States rival Apple, accusing it of using Nokia technology in its iPhones and iPads.

The fresh complaints in Britain, Germany and the Netherlands are part of an escalating battle between the two rivals in the smartphone arena that started more than a year ago when Nokia filed its first suits in the US.

Apple has also sued Nokia over patents. The two have repeatedly denied each other's claims.

"These actions add 13 further Nokia patents to the 24 already asserted against Apple in the US International Trade Commission and the Delaware and Wisconsin Federal courts," Paul Melin, Nokia vice president for intellectual property, said in a statement yesterday.