Thousands of people turned out for the free Juanes concert at Paris' Place du Trocadero, which was awash in red, yellow and blue, the colors of the Colombian flag.

Juanes kicked off the show, which coincided with Colombia's independence day, with an emotional rendition of the South American country's national anthem. Spanish singer Miguel Bose and other musicians were taking part in the concert.

Juanes was joined onstage by Betancourt, a French-Colombian politician who was freed this month after more than six years of captivity at the hands of the Revolutionary Armed Forces of Colombia, or FARC.

"A page has been turned," Juanes told the Associated Press, referring to Betancourt's July 2 liberation in a daring operating by the Colombian army. "But the book remains open and it's a heavy one."

Latin America's last major rebel army has been holding dozens of hostages in jungle jails, some for more than a decade. Colombia's government estimates the rebels have 700 hostages, but acknowledges that tally includes people kidnapped since 1996, many of whom have likely died.

For "all those who are waiting for the miracle of their release, we must continue to mobilize," said Betancourt, a former Colombian senator who was kidnapped while campaigning for the presidency in 2002.

Betancourt also spoke out for other prisoners held throughout the world, including Nobel Peace Prize laureate Aung San Suu Kyi, who is under house arrest in her native Myanmar, and Gilad Shalit, an Israeli soldier who was captured by Hamas-allied gunmen in 2006.

Speaking in Spanish, Betancourt addressed a message to FARC leader Alfonso Cano.

"Wherever you are in the jungle . . . understand that this is no longer a time to spill more blood," she said. "It's time to put down the weapons and exchange them for roses."