Police in Malta say they are investigating possible sightings of Madeleine McCann, 50 days after she disappeared from a Portuguese resort.
The search for Madeleine has been taken to Spain and Morocco
A number of UK tourists have reported seeing a child resembling the missing four-year-old in the island's capital, Valletta, and the resort of Sliema.
One said he saw a couple with a girl, who appeared to be wearing a black wig.
Meanwhile, yellow balloons will be released in 50 countries to keep up vigilance in the search for Madeleine.
Superintendent Pierre Calleja said Maltese police had received a report last Sunday of a possible sighting.
"Subsequent to this report, a full scale police investigation and a magisterial inquiry were initiated," he said.
"These investigations are actively in progress and all possible avenues are being pursued."
A spokesman for Madeleine's parents, Gerry and Kate McCann, said they were not giving credence to the claims at this stage.
Kites and doves
Madeleine went missing from Praia da Luz in the Algarve on 3 May.
Her parents, from Rothley in Leicestershire, will release 50 yellow balloons from the resort's beach today to mark the 50 days since her disappearance.
Supporters in countries including Ireland, Argentina, the US, Singapore and Australia will then follow suit.
In Afghanistan, campaigners will fly 50 kites emblazoned with pictures of the missing four-year-old, a report on the FindMadeleine website said.
And in California, 50 white doves will be released.
A message from the McCanns on the website said: "The objective is simple - after seven weeks missing, we must continue to ensure she is not forgotten."
The McCanns are also considering releasing a cover version of the Bryan Adams' song Everything I Do, I Do It For You, in an effort to raise more money for their campaign.
Speaking to Sky News Mr McCann said: "That song, at the minute, best reflects how Kate and I feel emotionally and how determined we are to continue searching for Madeleine.
Maltese newspaper In-Nazzjon reported that two tourists told police they had seen a girl matching Madeleine's description in Valletta.
Other reports said four more people had subsequently come forward with possible sightings.
A Maltese magistrate has taken evidence from those claiming to have seen Madeleine.
'Pitch black' hair
Ray Roberts, from Anglesey, north Wales, said he saw a child in Sliema wearing what looked like a black wig and being told "Get up, little girl" by a man of Arab appearance.
"It was obviously not his first language so it seemed odd that he had to speak to her in English," Mr Roberts said.
"As a father, their reaction did not seem natural."
He added: "Then I noticed the little girl's hair.
"It was pitch black, very thick and cut in an unusual style for a child that age - very much like a wig rather than real hair.
"The more I think about what I saw the more convinced I become that it may well have been Maddie.
"The oddness of it all played out in my mind until I got home then I realised I had to do something."
The McCanns' spokeswoman said they were not focusing on the sightings until more information was available from an official source.
"Their whole attitude from day one has been that they know there are going to be lots of bits of information, but if they expended energy on every single one of them what would they be like by now?" she said.