Two teenage girls who went missing a week ago have contacted their families.
But police say tracing Shadia Browne, 15, and Franchesca Nti, 14, both of Leyton, is still a priority.
This week their mother's issued an emotional appeal to the girls to return home.
Shadia's mother Silvia Browne, 47, also called on police to put more resources into tracking the girls.
The worried mother, of Duncan Road, asked the police on two occasions to track the whereabouts of the girls using the GPS of Franschesca's mobile phone.
A spokeswoman for the police said: "Police can confirm that all possible avenues of enquiry are being investigated in an effort to find the whereabouts of Shadia Browne and Franchesca Nti.
"There are no means of locating the girls that are not being considered.
"Despite both girls having been in contact with their families this week officers continue to treat this investigation as a priority."
The George Mitchell School pupils were last seen by their families on the morning of January 24.
The girls are described as black and approximately 5ft 6ins.
Shadia and Franchesca were both wearing school uniforms the day they went missing, but could have taken a change of clothes.
Police say there is a possibility the girls could be in Hackney or Tottenham.
Anyone with information is asked to contact the Missing Persons Unit at Waltham Forest on 020 3276 0989/0927 or via 101.