A 15-year-old girl was robbed by a balaclava-clad man in Kettering.
The incident took place at about 5pm on Tuesday, January 15, in Alexandra Street.
A police spokesman said the victim was walking when the attacker stopped her and stood in front of her.
She tried to carry on walking but he persisted and stole a small amount of money, believed to be £5, from her.
Officers attended the scene but did not find the attacker.
The force spokesman said the victim suffered no physical injuries in the incident but was left shaken by it.
The attacker is believed to be a tall white male, wearing a balaclava.
Officers are appealing for witnesses and have urged anyone with information to contact them on 101 or Crimestoppers anonymously on 0800 555111.