Members of Cork City Fire Brigade had to call for Garda backup twice as they responded to the bonfires on a green area in the Knocknaheeny area on Friday and Saturday night.
Some minor damage was caused to a fire engine during Saturday’s attack, but no firefighters were injured.
The Lord Mayor of Cork, Tony Fitzgerald, who represents the area, condemned the attacks, which come just weeks before the city’s traditional bonfire night celebrations.
“It is totally unacceptable that when our committed and dedicated fire crews respond to an incident, that they come under attack like this,” said Mr Fitzgerald.
“They should be allowed to do their work, to protect the public, in a safe environment.
“We must work closely with gardaí to ensure it doesn’t occur again.”
Mr Fitzgerald urged people to engage with the community-focused bonfire night celebrations, which will mark St John’s Eve in Cork later this month.
Fire crews were called to the Harbour View Rd area of Knocknaheeny on Friday night after reports that a bonfire was blazing on a green near the Barnardos facility.
One unit responded and came under attack from a gang of youths, who retreated about 30 yards and pelted the appliance with rocks and stones, and targeted fire crews as they fought the blaze.
Gardaí were called and the gang dispersed quickly.
Fire crews were alerted again, at around midnight on Saturday, to reports of a “substantial” bonfire on the same green area.
One unit of the fire brigade responded and came under attack again by a gang of up to six teenagers — believed to be aged from 15 to 18 — throwing rocks and stones.
They retreated as fire-fighters deployed, and Garda backup was requested again.
As they waited for Garda support, fire officers used torches to try and dazzle the youths and the fire was extinguished before gardaí arrived.
As the fire engine was leaving the area, it came under sustained attack again and suffered some minor damage.
There are a number of ‘hotspots’ across the city where fire crews expect to be attacked as they respond to bonfires.
A major operation is expected to be put in place again this year to provide Garda support to fire crews as they respond to incidents in the run-up to, and on bonfire night.