The parents of Madeleine McCann are spending a second weekend without their daughter, who disappeared from a Portuguese holiday apartment on 3 May.
Mother Kate attended a church service in the Algarve village of Praia da Luz where prayers were said for Madeleine.
On Saturday, Gerry McCann paid an emotional tribute to his daughter as the family marked her fourth birthday.
Relatives have released posters drawing attention to a distinctive marking in the youngster's right eye.
They hope that the picture - which clearly shows how Madeleine's pupil runs into her blue-green iris - will make her easily recognisable.
Rewards totalling £2.5m have been offered to anyone who can help with information leading to the safe return of Madeleine, from Rothley in Leicestershire.
Businessman Sir Richard Branson, footballer Wayne Rooney and children's author JK Rowling are among those who have contributed.
Sir Philip Green
Sir Tom Hunter
Sir Stelio Haji-Ioannou
Speaking at a special mass on Saturday, Kate and Gerry McCann called for people to keep looking and praying for their daughter, but also acknowledged the huge effort and resources being put into the search.
"Today we should be celebrating the fourth birthday of our daughter Madeleine," said Mr McCann.
"Instead we have had to remember what a normal, beautiful, vivacious, funny, courageous and loving little girl we are missing today."
Madeleine's uncle, John McCann, praised the amount of support the family has received from people in the UK.
He told the BBC on Sunday: "The general response has been magnificent - the wishes and the prayers that are coming in from all over the country has been astounding."
He also said the family was overwhelmed by the support from the congregation and the priest in the Algarve.
In the latest sign of solidarity, hundreds of Portuguese bikers are preparing to ride the length of the country distributing posters of the missing girl.
The official ground search for Madeleine in the Algarve has ended, but police say they still have significant leads to follow up.
The focus has shifted from a local search for Madeleine to an international child abduction inquiry, amid suggestions she may have been taken out of Portugal.
Some of the nine people who were questioned on Thursday and Friday - mainly family and friends of the McCanns - may be asked to make formal court statements, BBC correspondent Alison Roberts said.
Police have said none of the people in the McCanns' close circle is a suspect.
Detectives are also continuing to cross-check CCTV footage of several cars with witness statements in their efforts to identify a possible abductor, our correspondent said.
Police have declined to confirm or deny reports about any possible leads, citing Portuguese law.
The international number for Crime stoppers is +44 1883 731 336. People with information about Madeleine can call anonymously.