President Bill Clinton: "We've got to quit fooling around with this"

"I know this stuff sells - but that doesn't make it right," Mr Clinton said.

Speaking at the White House, the US president announced a million-dollar, 18-month investigation into the issue.

President Clinton says it is time for restraint

He said America's children were being fed a daily dose of violence which was clearly affecting their values and behaviour.

He said the average American child saw 40,000 dramatised murders by the time he or she turned 18.

He urged Hollywood to limit the amount of violence young people were exposed to, and said the presidential study would focus on whether advertisers were trying to sell children adult-only products.

President Clinton said he realised it was time for restraint after reading a video-game advert urging potential buyers to get in touch with their "gun-toting, cold-blooded, murdering side".

Shooting issue

The president and others have argued that the Colorado school shootings produced a profound cultural shift in America, and a popular demand for change.

TV networks have dropped some violent programmes in the wake of the school killings, but BBC Washington Correspondent, Rob Watson, says it is unlikely that there will be major changes in the entertainment industry.

The president's Democrat Party receives considerable funding from Hollywood.