The first happened at around 6.20pm on Monday, when a man exposed himself to two 11-year-old girls in Front Street East, Bedlington. He is described as being aged 40-50 years-old, of large build with short, balding hair and wearing a navy tracksuit.
The second incident happened at 12.15pm on Tuesday, when a man was seen to perform a sex act on himself in Gallager Park, Bedlington.
He is described as being white, aged late twenties to early thirties and was wearing a light coloured baseball cap with light coloured top and bottoms.
The third happened in Cramlington at 4.35pm yesterday, when a man exposed himself to two teenage girls in Seven Oaks Park, Dudley Lane. He is described as a white man aged around 50 and between 5ft 6 - 5ft 8 inches tall. He had a large build, bald and was wearing a royal blue hoody with grey bottoms.
Inquiries into all three incidents are ongoing and anyone with information to help is asked to contact police.
Extra officers are on patrol in the area carrying out patrols and speaking to people to offer reassurance.
Anyone with information to help is asked to contact police on 101 quoting references 1064 21/03/16 / 0470 22/03/16 or call Crimestoppers anonymously on 0800 555 111.