AMSTERDAM, Dec 22: Two of the world's top mobile phone makers said more research is needed into the potential for cell phone radiation to damage DNA, following a laboratory study by 12 European institutes which found harmful effects.

Motorola and Sony Ericsson, the world's No. 3 and No 6 mobile phone makers, said they needed further scientific evidence that radio waves harm body cells and damage DNA. The results of the European Union-funded study, which was made available on a website this week by the coordinating German institute Verum, first needed to be published in a scientific magazine, said Sony Ericsson, Japanese-Swedish venture.

"Then, the published results have to be balanced with the total picture of research. There are other studies published that failed to show any link between radio signals and DNA damages," the company said in an e-mailed response to questions.

A Motorola spokesman in Washington said his company was also "awaiting evaluation by the scientific community". Verum said it was in talks with several magazines and a publication decision was expected within months.

The four-year research project measured a significant increase in single and double-strand DNA breaks in human and animal cells after being exposed to electromagnetic fields that are typical for mobile phones.

The damage could not always be repaired by the cell. DNA carries the genetic material of an organism and its different cells. "There was remaining damage for future generation of cells," project leader Franz Adlkofer said. -Reuters