The 18-year-old woman was last seen in central Uddevalla, several media outlets report.
On Friday, a murder investigation was opened to broaden the search and expand the police's powers.
"I want to be clear that nothing concrete has emerged that indicates that she has been the victim of a crime," said Martin Öhman, police chief in Västra Fyrbodal, on Friday.
Earlier on Saturday, he told P4 Väst that the search for the woman had been going on all night and morning.
We have not found any new tracks that we consider interesting.
In addition to the police, the Armed Forces are also participating in the search.
"We have searched with dogs and hand-swept parts of the terrain to ensure that we do not miss any tracks," Öhman said.
