Dublin fire brigade has said its crews will refuse to attend emergency calls at a halting site in Finglas, north Dublin, without Garda assistance.
The decision was taken after six crew members were attacked when they responded to a 999 call in the Dunsink Lane area early on Sunday morning.
The incident happened at 2.30am on Sunday, when the six-man unit arrived at St Joseph's Park in response to an emergency call reporting that a caravan was on fire. It was then "ambushed" by a large group of men, who threw more than 10 large patio stones at the windscreen and side windows, according to a spokesman.
"They were ushered in [ at the gate] and they weren't told that there could be a problem. It was very orchestrated and premeditated, and they weren't young children - they were adults," said Paul Carolan, Dublin Fire Brigade's health and safety officer.
Mr Carolan said the crew were "genuinely traumatised" by the attack and had been on sick leave since. "I was speaking to one crew member who has 20 years' experience in the fire brigade. This guy was scared, he said this was the most frightening experience he ever had." Some crew members had feared their lives were in danger.
Sunday's incident was the sixth such attack on firemen in the capital in the past month. "We get about 120,000 calls a year in Dublin, and 99 per cent of the time all we get is good will, but the severity of these attacks is new," said Mr Carolan.
The problem - which arises not only in certain Traveller sites but in areas across the city - could only be confronted if community leaders and elected representatives took a lead, he said.
Travellers support group Pavee Point strongly condemned Sunday's attack and urged anyone with information to notify gardaí.
"Unfortunately issues of antisocial behaviour affect some Traveller sites as they do other areas. Travellers are deeply concerned by this both in terms of the harm caused to service providers as well as to their own community - including living in fear, disruption to service provision and generalised negative publicity," it said in a statement.
Meanwhile, Fianna Fáil TD Charlie O'Connor said those who attacked fire and ambulance crews would face prison sentences of up to seven years under legislation due to be passed by the Oireachtas this week.
Under the proposed section 30 of the Criminal Justice Bill, anyone who obstructs emergency crews will also face a fine of €2,500 and up to 6 months jail.Unions representing emergency crews would prefer these measures to be contained in standalone legislation, such as that recently enacted in Scotland. They say this would make them easier to promote and enforce.