The officers are today recovering in their homes after being treated at the Mid-Western Regional Hospital.
Michael Ryan, Limerick fire chief, said: "The attack on our firefighters is shocking and disgraceful."
He said they sent three appliances and a crew of 12 to attend to the two houses.
"When they arrived and began the work of extinguishing the blaze they were attacked by a group of youths throwing rocks.
"In fear of the safety of his crew, our incident commander drew back from the incident and requested assistance from gardai.
"However, two firefighters were injured and the windscreen of a high-reach fire service appliance was smashed with rocks."
Mr Ryan said: "Both of the injured firefighters were sent to the Mid-Western Regional Hospital for urgent medical attention. They will be absent from work while they recover from their injuries.
"The damaged appliance has been taken out of service and is awaiting repair. As a consequence of the attack this appliance is unavailable for further emergency calls should they occur."
The fire crews continued to deal with the blaze after the attack.
Mr Ryan said: "The crew that attended this call are all dedicated professionals who are proud that they save lives and property in Limerick.
"Firefighters, like all emergency services personnel, have a job to do and they deserve to be able to do it in safety, and without fear of assault. We are all angry and shocked that they were subjected to such a cowardly attack, but we know that this was the action of a small minority in an area where we have a good relationship with the community."