He Yun Jin, Lin Xiu Ming, and Weng Mei Fang disappeared on 30 March

Weng Mei Fang, 15, and 16-year-olds Lin Xiu Ming and He Yun Jin applied for asylum in Newcastle after arriving in the UK last month.

They have not been seen since 30 March, when they left their Elswick Lodge home, accompanied by a man.

It is believed the girls may have been taken to London.

Det Ch Insp Jim Napier, from Northumbria Police, who is leading the investigation, said they are treating it as a missing persons enquiry and the main concern is the girls' welfare.

'Great concern'

He said: "We know nothing about their movements prior to arriving in this country, although they are believed to be from the Sichuan and Hunan provinces, and Newcastle appears to have been a transit city which they stayed in for just three days.

"While it is a concern these girls could end up being exploited, for example in prostitution, there is currently no evidence to suggest that is the case. They could well be working in a legitimate trade.

"All we are interested in is locating these girls and would ask them, or anybody who has information about their whereabouts, to come forward to let us know they are safe and well."

The girls arrived in the UK last month, after flying from Paris to Newcastle to claim asylum.

They were housed by social services while their applications were being processed.

A caseworker for the National Missing Person's Helpline said they had "great concern" for the girls, who could suffer long-term physical and psychological damage if they are abused.