A woman was robbed by three men in "a frightening incident" in Newbury at the weekend.
The 19-year-old was on her mobile phone when she spotted a man standing at the junction of Enborne Road and Kingsbridge Road.
Three men including the man at the junction then ran at her and grabbed her around the arms.
She shouted at them to let go until one of the men put his hand over her mouth while another snatched the mobile out of her hand.
The robbers fled along Kingsbridge Road towards Fifth Road with the woman chasing after them into Buckingham Road, where she lost sight of them.
The woman's lip was cut during the robbery and she did not require hospital treatment.
Her phone was later found when she revisited the scene with police officers.
The robbery took place between 5.30pm and 6.45pm on Saturday, April 8.
Specialist investigator Tracy Cole said: “Saturday was a warm and sunny day, and there were lots of people in the area at the time.
“I am hoping that there will be several witnesses who saw the incident, or who saw a young woman chasing after three men.
“This was obviously a frightening incident for the victim, and we are supporting her during this time.
“If you have any details which could help our investigation, please contact the Thames Valley Police non-emergency number 101.”
Police have released descriptions of the attackers.
The first man is described as white, aged about 24 to 26, with an average build and short dark brown hair. He may have had tattoos on his neck and right forearm, and was wearing light grey tracksuit bottoms and a grey zip up top.
The second man was white with black hair and was wearing black tracksuit bottoms and a blue jumper.
The third man was white with dark brown hair, aged about 26 or 27 and was wearing a black Adidas tracksuit.