Detectives investigating the rape of two women who were abducted and attacked are looking for a white man with a bald head or shaved blonde hair.
The first victim was abducted in Chingford, north London, early on Thursday while the second was taken 12 hours later in Edgware.
Both women managed to escape their captor following a struggle in Osborne Road, Watford, the Met Police said.
The suspect is described as aged in his late 20s to early 30s.
He has a short beard, tattoos and drove a silver or grey-coloured Ford S-Max people carrier.
Detectives said the women were “randomly selected” by the same attacker.
“We are continuing to speak to both women to obtain a complete picture of what happened after they were abducted,” Det Ch Insp Katherine Goodwin said.
“At this stage we believe that the suspect travelled around north London and Hertfordshire in his car from the early hours of Thursday 25 April and he may have come into contact with other members of the public.
“If you were in these areas on Thursday and were approached by a stranger in similar circumstances, or saw anything that roused your suspicion or made you feel uncomfortable, get in touch now.”
The detective added that her team was working closely with officers in Hertfordshire to establish potential links the suspect might have to the area.