A woman suffered injuries on the breasts and right hand during a robbery on the Middle Ring Road 2, reported Harian Metro.
The incident happened at 3am on Monday near Taman Tasik Metropolitan as the 27-year-old was driving home to Kepong.
City CID chief Senior Asst Comm Datuk Zainuddin Ahmad said the woman saw four motorcyclists riding dangerously and tried to avoid them but they surrounded her car.
"She lost control of her car and hit the divider. The suspects opened the car door and slashed her," he said.
He said the motorcyclists, who wore full-faced helmets, stole the woman's valuables, including her wallet and mobile phone.
He said passers-by helped to take the woman to hospital where she received 10 stitches for her injuries.