Hundreds of thousands of Cubans have packed into Havana's Revolution Square for the biggest outdoor concert in the island's post-revolution history, featuring artists from Spain and Latin America as well as domestic performers.

Some estimates put the crowd for the five-hour concert, headlined by the Colombian superstar Juanes, at about a million, or almost one in 10 of the population.

The event was billed as a peace concert aiming to help end Cuba's international isolation, but has angered some Cuban exiles in Miami, who smashed Juanes CDs and promised a boycott of his music.

Juanes, whose fusion of Colombian and rock sounds has made him a superstar in the Spanish-speaking world and bagged him 17 Latin Grammy awards, has also reportedly received death threats for taking part in the concert, although he did get the backing of some jailed Cuban dissidents for his decision.

"We came to Cuba for love. We have overcome fear to be with you and we hope that you too can overcome it," Juanes said as he took to the stage to enormous cheers. "All the young people in the region, from Miami in the United States and in all the cities, should understand the importance of turning hate into love."

The government laid on hundreds of buses to take people to yesterday's show, which was held in ferocious heat. Several people were treated for dehydration and exhaustion before the concert.

Few overseas rock bands play in Cuba. In 2001 Welsh band Manic Street Preachers played to an audience of 5,000, including Fidel Castro, at a concert hall in Havana.