Yesterday's service was organised by Forever Searching – a charity which supports relatives of missing and exploited children – to mark International Missing Children's Day.
"People say to us what we're going through must be terrible, but we are not Madeleine's parents, and we can't even begin to imagine what they're feeling. Days such as this do a great job of letting people know there's help out there."
We are holding the mass on International Missing Children's Day to highlight the issue and make people aware it is a concern all over the world."
A ball at the Walkers Stadium on Sunday night raised money for the charity. A signed Liverpool football shirt and Oasis concert tickets were auctioned.