It is possible that this type of behaviour may constitute harassment ,see the related questions in Related Information. However, it would probably be best if you first made contact with your local neighbourhood policing team who may be aware of other incidents and know the identity of the youths involved (if you don't). Police Community Support Officers are a valuable source of information.
The officers may be able to consider applying for civil injunctions or Criminal Behaviour Orders if the same youths are persistently causing a community problem with these types of nuisance activities. These types of problems ,may not be solved straight away though, a lot of enquiries, research and observations may be required by both officers and members of the community in order to combat this anti-social behaviour.