Firefighters in Wales walked out at midday in a five-hour strike.
Along with colleagues in England, they are in a long-running dispute over pensions. The UK Government says it has met union leaders on many occasions and there is 'ongoing communication' to find a solution.
Fire Minister, Brandon Lewis MP, says the government is offering firefighters "one of the most generous pension schemes in all the public sector."
By calling unnecessary strike action, the FBU has shown it is not serious about finding a resolution to this dispute for its members and stands only to further damage firefighters’ standing with the public.
The government has met with the FBU on many occasions, most recently during April, and has remained in ongoing communication to find a solution.
The deal on the table gives firefighters one of the most generous pension schemes in all the public sector, and the proposals protect the earned rights of a higher proportion of members than any other public sector scheme. Nearly half will see no change and even firefighters who are not protected will see no change until 2015.
Under the new scheme, a firefighter who earns £29,000 will still be able to retire after a full career aged 60, get a £19,000 a year pension, rising to £26,000 with the state pension. An equivalent private pension pot would be worth over half a million pounds and require firefighters to contribute twice as much.
The UK Government has been accused of "burying its head in the sand" in the ongoing pensions dispute with the Fire Brigades Union.
Firefighters in Wales are joining their colleagues in England and Scotland later in the latest strike action over the row.
After three years of negotiations and an intense four months presenting an indisputable, evidence-based case for the need to ensure a pension scheme that takes into account the unique occupation of firefighting, the government is still burying its head in the sand.
Several members of government were only too keen to praise firefighters during the winter floods, but their words amount to nothing when they simultaneously ignore issues that threaten the future of firefighters and their families.
Nevertheless, we remain totally committed to resolving the dispute through negotiation, and are ready to meet to consider a workable proposal as soon as possible.
South Wales Fire and Rescue Service say they received 'multiple calls' of flooding in Treorchy whilst on strike last night.
Up to 30 homes were evacuated in the Rhondda Cynon Taf area and a rescue centre was set up to help residents.
Members of the Fire Brigades Union across England and Wales staged their sixth walk-out since September in a row over pensions.
The strike happened between 6pm and 10pm.
Assistant Chief Fire Officer Rod Hammerton said he was pleased with how South Wales Fire and Rescue Service had managed its services during the strike action.
“As expected, the number of Firefighters from South Wales Fire and Rescue Service who chose to strike was high, which resulted in a large reduction in the resources that we had at our disposal.
"As such, we were unable to provide the same high level of response to incidents as we normally would and as a consequence prioritised our response to those in most critical need."
Rod Hammerton also added that contingency plans were put in place in collaboration with South Wales Police and the ambulance service to "ensure that the necessary advice was available to ensure that the resources that the public needed were available as quickly as possible."
It is unclear whether there will be further action by firefighters.
Fire crews across Wales will strike for the fourth time tomorrow in an ongoing dispute over pensions.
Firefighters who are forced to retire before 60 as a result of declining fitness could now receive pensions of just over £9,000 a year as a result of the latest government proposals.
The government has, until recently, claimed that firefighters who work for 40 years would receive £19,000 a year.
Fire Brigades Union general secretary Matt Wrack said: "After 35 years of service - and paying at least £4,000 a year - firefighters could now receive just over £9,000 a year, or the sack, simply because fitness declines as they get older.
"Firefighters simply want an affordable and workable pension that reflects the job we do. But with employee costs going up, firefighters are being priced out making the scheme threatening its sustainability.
"We're keen to resolve this through negotiations, but the government is simply ignoring all the evidence we have submitted."
The strike will take place between 10am and 2pm on Wednesday. Firefighters are also voting in a ballot over additional forms of industrial action.