A gang of 30 youths hurled missiles at firefighters who had been called to put out a bin fire.
Cleveland Fire Brigade said it received repeated "entrapment calls" to the blaze in Hemlington in Middlesbrough in the early hours of Monday.
When they arrived they were ambushed, leaving a fire engine damaged. Fire chiefs described the attacks as "completely unacceptable".
Cleveland Police officers were also targeted during the fracas.
An investigation is under way.
The brigade's senior area manager Steve Johnson said it would not tolerate such attacks.
"It is completely unacceptable for our staff to be subject to violence and acts of vandalism whilst protecting the public.
"Our job is made even more difficult by the thoughtless actions of a minority who in this instance, deliberately set fires and damaged a fire engine, making that vehicle unavailable for emergency response.
"Deliberate fires such as these divert resources and run the risk of us not being able to respond to a life threatening incident."
A police spokeswoman said they received reports of a "large group" causing damage to properties and vehicles and burning items in the Cass House Road area.
The brigade said it had seen 13 attacks on crews between March and May, including a tree trunk being thrown through the windscreen of a fire engine and bricks hurled at firefighters as they tackled a garden fire that was threatening to spread.