Detectives are scrambling to find the men behind a third shocking incident on a girl, 13, in Gloucester.
The teenager was approached by masked men in a blue van in the Dancers Hill area of Abbeymead, at 8pm on Saturday, July 22.
The frightening assault is the third reported in just one week in the area with children out of school for the six week summer holidays.
In a quick thinking bid to escape the men the girl ran down an alleyway.
The teen said one of the men wore a black jacket and a black mask through which his brown eyes could be seen.
In another incident two girls were approached on Tuesday, July 18 by two men in a blue transit van.
Despite the girls walking along in broad daylight they were approached by the vehicle before men offered them a lift home near, Barnwood Park Arts College.
The incident happened around 3.50pm before the van drove off towards Abbeymead.
On the same day a girl was approached at around 4.20pm on Norbury Avenue, Matson and the driver asked if she wanted to get in.
There were two men in the van, and the driver was described as white and in his twenties with blonde hair.
The van had a foreign number plate, possibly Irish.
Police have warned parents to let their children know the importance of vigilance, and have asked all incidents of being approached by strangers to be reported.
Schools in the area have been alerted and reassurance patrols by uniformed police are taking place.
If you have seen this van, or have any information that can help police with their enquiries, please call 101 quoting incident number 181 of July 22.
The incidents come as a man was arrested in Manchester after being accused of grabbing a girl, 5, outside Primark in the city centre.