The parents of missing British girl Madeleine McCann said they have been given hope by the discovery of three women kidnapped in the United States a decade ago.
"The discovery of these young women reaffirms our hope of finding Madeleine, which has never diminished," Kate and Gerry McCann said, a week after marking the sixth anniversary of their daughter's disappearance.
Madeleine was three when she vanished from the family's holiday flat in Praia da Luz on Portugal's south coast in May 2007, while her parents were at dinner.
The toddler's disappearance sparked an intense media frenzy and an international police investigation.
The couple said that the case of Amanda Berry, Gina DeJesus and Michele Knight - who all went missing in the US city of Cleveland a decade ago, and were found in a house on Monday - was "further evidence that children are sometimes abducted and kept for long periods".
"So we ask the public to remain vigilant in the ongoing search for Madeleine," the McCanns said.
"Our thoughts are with the women in America and their families."
A potential new lead in the McCann case came to nothing earlier this year when DNA from a girl in New Zealand bearing striking resemblance to Madeleine proved that it was not her.