Fire crews on Tyneside were targeted by youths on three occasions in a week.
A crew responding to a wheelie bin fire in Denton was attacked by 20 youngsters on Sunday, and on Tuesday rocks were thrown at an appliance tackling a rubbish fire in Gateshead.
On Thursday night a gang of girls threw bottles and stones at a crew attending to a wheelie bin fire in Newcastle.
Tyne and Wear Fire and Rescue Service has asked parents to remind children the service is there to protect them.
A spokesman said the attacks "not only hinder our crews in their work but distract them while they extinguish fires and stop them spreading or causing further damage".
He added: "We'd like to appeal to the parents and guardians of young people to remind them that we are here to protect them and respond if they or their families need help, not to be attacked.
"If a firefighter is injured or an appliance damaged, they are out of service for days or longer which could have serious consequences for the public if we have to respond to serious or major incidents."