Police have used dogs and mountain rescue teams to try to locate a woman missing for two weeks.
Svitlana Krasnoselska, 40, originally from Ukraine, was last seen near her home in Micklefield, near Leeds, at 05:00 BST on 3 April.
West Yorkshire Police said the search was concentrated around Micklefield but had found nothing.
Officers said they were very concerned for her welfare as her disappearance was completely out of character.
The mother-of one has lived in the UK for 12 years.
Officers said she had also recently lived in York and Halton, Leeds, before moving to Micklefield.
Det Insp James Entwistle said: "This is a genuine mystery. We have no idea what has happened or where she has gone.
"It is completely out of character for Lana.
"The search is around her home address and we have used mountain rescue and dogs to make sure we have cleared that area."