Police are appealing for information after a robbery on Harlaxton Road in Grantham.
The 17-year-old victim was making his way home at around 11.20pm on Friday when he was shouted at by a man in a stationary car thought to be red or orange in colour.
Three men then approached him and threatened him before stealing his mobile phone and Nike rucksack. The men are thought to be in their early 20s.
The victim sustained minor injuries which did not need medical attention.
Anyone who witnessed the incident or who has any information as to the offenders should call Dc Roberts on the non-emergency 101 number, quoting incident number 503 of February 28.