Two women were dragged into a car and raped after being “randomly selected” by the same attacker, police have said.
The first victim was abducted from a street in Chingford, north London, early on Thursday, while the second was captured 12 hours later in Edgware – more than 10 miles away.
Both women, who are in their 20s, managed to escape their captor following a struggle in Osborne Road, Watford, the Metropolitan Police said.
The Met has appealed for information.
It said the women made their escape from the attacker, described as a white man of muscular build, at about 14:30 BST on Thursday.
Det Ch Insp Katherine Goodwin said: “This was a terrifying ordeal for both women. At this stage there is nothing to suggest either victims were specifically targeted for any reason, but both appear to have been selected at random.
“A number of active leads are being followed up urgently including reviewing CCTV footage and forensic analysis.”
Ms Goodwin said her team was also working closely with officers in Hertfordshire to establish potential links the suspect might have to the area.
She added: “Stranger attacks like this are extremely rare. That being said, I would urge everyone in these areas to remain vigilant and report anything suspicious to police immediately via 999.”