BERLIN - Germany's top radiation official says that people, especially children, should minimize their use of mobile phones as a health precaution.

``In general, cellphone calls should be kept as short as possible,'' Wolfram Koenig, head of the Radiation Protection Agency, told the Berliner Zeitung. ``Parents should keep their children away from this technology as much as possible.''

In the interview scheduled for publication on Tuesday, he also advised car drivers to avoid using mobiles completely.

Earlier this year, the U.S. cellular telephone industry came under renewed legal attack in a series of class-action lawsuits claiming that cellphones pose a series of health risks ranging from infections to brain damage.

Most similar previous cases have been dismissed.

Studies published recently in the New England Journal of Medicine (news - web sites) and the American Medical Association have found no evidence that the phones cause brain tumors in the people who use them.

Koenig said there was no scientific evidence of health risks through cellphones, but he warned of possible hidden risks through thermal and biological effects.

He said science must urgently address whether cellphones could be linked to a series of different illnesses.