Amnesty International says it hopes to raise the awareness of youth when Bruce Springsteen, Peter Gabriel, and other rock stars launch a worldwide concert tour dedicated to human rights.

The six-week tour, which opened Friday night at London's Wembley Stadium, will go to 20 cities in North America, Asia, Hungary, Africa and Latin America.

The $23 million extravaganza is to mark the 40th anniversary of the United Nations Universal Declaration on Human Rights. Organizers expect sell-out crowds but stress that raising money is not the sole intention.

"This tour is not about charity, it's about justice," said Jack Healey, head of the U.S. division of the organization, which monitors human rights abuses and won the Nobel Peace Prize in 1977.

"What we're talking about is human rights and the seriousness of the issue . . . there's too much torture, too many people being killed," he said.

The pop stars taking part are both realistic and romantic about playing for human rights.

"When I was younger I thought maybe you could pick a guitar up and you could change the world," Springsteen, 38, said at a news conference Thursday.

"I don't really believe that any more. But I do believe you can save a life," he added. "Someone comes to the show, they hear the message, they hear what we are singing about, they go home, they write a letter and someone gets out of prison early. That's pretty good."

Springsteen is sharing a bill on the 35,000-mile tour with Gabriel and Sting, American folk singer Tracey Chapman and Sengal's Youssou N'Dour.

More than 1 million people are expected to see the concerts live, with televison audiences of many more.

Ticket prices vary from rich to poorer countries - $37.60 in London and $3 in Budapest, Hungary. The final concert is scheduled in the Argentine capital, Buenos Aires, on Oct. 15.

The U.S. sports goods manufacturer Reebok has underwritten the cost of the tour, and organizers say they hope it will break even.