The mother of missing Madeleine McCann has appealed to whoever is holding the three-year-old not to hurt her.
Madeleine from Leicestershire is feared to have been abducted from a holiday apartment in Portugal on Thursday.
Her mother Kate McCann said: "Please do not scare her. Please let us know where to find Madeleine or put her in a place of safety."
Portuguese police said the search was continuing, but they could not say for certain whether she was still alive.
In a statement they said they had widened their search to nine miles (15km) from the Algarve village of Praia da Luz and were working closely with Interpol and Europol.
Asked whether he thought Madeleine was still alive, Chief Inspector Olegario Sousa said: "It is very difficult to give you an answer because I have not facts to sustain that the child is alive or not.
"We're searching for the child and until the moment she appears we can say nothing more because we are not magicians."
He added it was not possible under Portuguese law to give further details.
Mrs McCann, who had asked to speak to the media, said: "We would like to say a few words to the person who is with our Madeleine, or has been with Madeleine.
"Madeleine is a beautiful, bright, funny and caring little girl. She is so special. Please, please, do not hurt her.
Speaking with husband Gerry at her side, she added: "We beg you to let Madeleine come home. We need our Madeleine."
Her final sentence was in Portuguese - "Por favor, devolva a nossa menina" - which means "Please give our little girl back".
About 50 volunteers have been helping to search the area for signs of the girl, including the clothes she was wearing when she vanished.
Her family confirmed she was wearing white pyjama bottoms with a small floral design and a short-sleeved pink top with a picture of Winnie the Pooh character Eeyore.
The pyjamas, bought in Marks and Spencer last year, had the Eeyore written in capital letters.
Police have a sketch of a suspect but will not elaborate on their evidence "to safeguard the child's life".
Portuguese police say they believe Madeleine is alive
The toddler is believed to have been taken from her bed while her parents were eating at a nearby restaurant and regularly checking on her and their two-year-old twins Sean and Amelie.
BBC correspondent Robert Hall said he had been out with a volunteer search team - made up mainly of British expats and tourists - on Monday.
Although they said they had not been well briefed by police, they did know one item they were looking out for was Madeleine's clothing, our correspondent said.
Dave Felton, an expat from Manchester who lives in the village, said people were still hoping that Madeleine was "safe and sound somewhere".
Around the marina in the nearby town of Lagos, maritime police have been searching amid claims a man was seen with a small girl in the area.
Marina worker Joao Riveiro said a number of officers had been searching and making inquiries.
"Police without uniforms moved around a lot about two days ago. They moved around and were asking questions."
Officers have taken records of all boats booked into the marina between 27 April and 6 May.
Along the nearby coast police have checked a cave complex at Ponta da Piedade, with the help of volunteer canoeists.
Police, who have received thousands of calls, have not reported any progress in their investigation since saying on Saturday they thought Madeleine had been abducted but was alive.
They are coming under increasing pressure to give more information, but correspondent Robert Hall said it was not the style of the Portuguese police to provide constant updates to the media and public.
At the press conference, Chief Inspector Sousa said that he was not able to publish an artist's impression of a suspect because he feared it may harm the case.
Asked whether the family were being kept informed, he said: "The family is the number one interest in the case but even then, they must be a little far from the investigation."
Local mayor Julio Barroso told BBC News 24 work was going on behind the scenes to try to find Madeleine.
"Our judicial police are following all the signs, and they are working very hard for all these days and they have many many people involved," he said.
He said about 130 people were working on the case, including 80 detectives, some of whom had come from the capital Lisbon. The team also involved local and maritime police, firefighters, volunteers and members of the Red Cross, he said.
When asked how he felt about what had happened he said: "In Portugal we say 'hope is the last thing to lose'."
At the weekend, officers were stopping cars on roads and searching abandoned homes and scrubland in the surrounding Algarve countryside.
Airports across the country are on alert and police believe the toddler is still in Portugal.
They have been showing locals what one called "a vague sketch" of a suspect.
It is believed the image shows only the rear view of a man.
Mrs McCann found the outside shutter and window to Madeleine's room had been opened and her daughter missing shortly before 2200 local time on Thursday.
Mark Warner managing director David Hopkins said in having a meal nearby in what was a "very safe environment", the McCanns had "done nothing that I'm sure many parents wouldn't have done".
A spokesman for the company said two holiday bookings at the resort had been cancelled and six had asked to go to another site.