Merseyside Police issued 18 notices to young people after dispersal zones were put in place in Kirkby and Huyton at the weekend.
The Section 34 dispersal zone was introduced following an increase in reports of anti-social behaviour, including reports of groups of youths causing criminal damage and threatening people in Huyton and drugs use and large quad bikes being driven in areas of Kirkby.
High-visibility patrols in uniform and plain clothes were patrolling the streets throughout the weekend, and as result of the orders five notices were handed out for incidents in Huyton and 13 notices were issued to youths in Kirkby.
Officers in Huyton also took a 13-year-old boy home under suspicion of causing criminal damage on Friday 6 February.
Neighbourhood Policing Inspector David Hassett said: “These dispersal zones are one of the many tools we use as a proactive measure to prevent anti-social behaviour from taking place.
“These recent incidents have caused significant criminal damage to houses and businesses in Knowsley. I hope the arrest and notices issued reassures our residents and those who work in Kirkby and Huyton that we are committed in preventing anti-social behaviour, crime and disorder in these communities.
“Anti-social behaviour is totally unacceptable, and we understand the impact it has on those living in the area, businesses and residents, this why it is one of our community priorities.
“If you are a parent or guardian of a young person in these areas please speak with them about this type of behaviour, what they are up to and friends they are with to further assist us in dealing with these types of incidents and to protect them from any serious crime.”