Thames Valley Police is appealing for witnesses following incidents of assault and sexual assault in Bletchley.
The incident of sexual assault occurred at around 7.30pm on Monday 25 September in Manor Road and Eaton Avenue.
A girl in her twenties was followed by a male down an alleyway and touched over her clothing.
The incident of assault occurred at around 7.30pm in Ennerdale Close on Thursday (28/9).
A girl in her teens was walking with a friend in the Lakes Estate when they were approached by a male.
When they told him to go away, the girl had her hair pulled and was dragged to the floor.
The offender pulled out a knife which was kicked away by the victim.
Police believe the two incidents could be linked.
Investigating officer, Detective Constable Paul Cushing-Cena, based at Milton Keynes police station said: “We are investigating these incidents and at this stage believe they could be linked.
“I am appealing for anyone who witnessed either of these to please get in touch with us by calling 101 or making a report online quoting reference 43230436696.
“Alternatively, if you wish to remain anonymous, you can contact the independent charity Crimestoppers on 0800 555 111.”
A 14-year-old boy from Milton Keynes has been arrested on suspicion of sexual assault, possession of an offensive weapon, assault, and harassment.
He has been released on bail.