Nida Ul-Naseer's sister Naila: 'She's not in trouble. We all love you. Just come home.'
The sister of teenager Nida Ul-Naseer, missing from her south Wales home for six days, has made an emotional appeal for her to come home.
Naila Anwar said the family in Newport "miss Nida desperately" and stressed she was not in any trouble.
Gwent Police say Nida, 18, had an argument at home which could have upset her.
But they added there was no suggestion she was picked up in a vehicle.
Officers are extremely concerned for her welfare as she is without her medication, which could make her anaemic.
"The most worrying thing is she's missed mum's birthday, which is not like her," Ms Anwar told a news conference.
Ms Ul-Naseer was last seen taking out rubbish at her home in Linton Street at about 20:00 GMT on 28 December.
Gwent Police have searched open areas around the family's home and have made house-to-house inquiries.
Nida Ul-Naseer was last seen taking out rubbish at her home
Ms Anwar urged her sister to get in touch and asked anyone who knew where she might be to contact police.
"We are missing her, we just want to tell her that she's not in trouble. We all love her, we all love you Nida. Just come home," she said.
"Please, please tell police if you know anything - anything about her - please call police on 101. Please help us."
Gwent Police's assistant chief constable, Paul Symes, said up to 40 officers had been involved in the search for Ms Ul-Naseer since she went missing.
They have been trawling through hours of CCTV footage to try to locate her.
Officers have been working closely with Ms Ul-Naseer's family to try to find out more about her friends and lifestyle.
Her disappearance is "particularly out of character", Mr Symes said, and officers are "extremely concerned" for her welfare.
When she was last seen Ms Ul-Naseer was wearing jeans and a black top.
She is is of Asian-Pakistani appearance and has long dark hair, slim and 5ft 3in (1.6m) tall.
Gwent Police have asked anyone with information to contact 101 quoting log number 448 28/12/13.