Police say they are tackling an increase in drinking and anti-social behaviour which resulted in one young person being taken to hospital.
Peterlee Police say the groups of youths are also starting fires in the town and then hurling abuse at firefighters.
Now, officers are appealing for parents to help them tackle the behaviour of these young people.
A spokesman for Peterlee Police said: "Over the past few weeks, we have dealt with an increasing amount of youth-related anti-social behaviour including deliberate fires.
"Firefighters, whilst on scene at these fires, have received an increasing amount of abuse and provocation, which has resulted in police attendance.
Officers have visited and spoken to a number of parents in relation to these offences.
"We also have seen a rise in alcohol-fuelled instances with youths. On one of these occasions, a youth had to be transported to hospital by ambulance when they were found unresponsive.
"We ask parents to be aware of these issues and speak with their children about their behaviour when they are out with friends."