Firefighters in the West Midlands went back to work after the first of a series of strikes over payments and changes to shift patterns.
West Midlands firefighters walked out on strike on Monday
Monday evening's action will be followed by another walkout on Thursday morning unless the two sides reach a settlement.
A military force providing emergency cover responded to 21 incidents.
Brigadier Chris Murray, head of 143 West Midlands Brigade, said the task force had "coped well".
Fire Brigades Union (FBU) members unanimously rejected a revised offer from the fire service on Sunday night and last-minute talks ahead of Monday's action also broke down without success.
An offer to compensate staff for working anti-social hours and for additional travel costs following the introduction of a new shift system was rejected.
At the end of Monday's action Pete Gallagher, West Midlands FBU brigade secretary, said: "We don't want to take strike action but local managers are refusing any attempts at compromise.
Third strike date
"Managers want major changes to shifts that force us to finish work much later and work more days in the year.
"These clearly have a major impact on family life as well as working life."
A task force of 380 joint service personnel, equipped with 26 modern fire engines, are providing basic emergency firefighting cover during the strike periods.
Their engines have been stationed at 11 Territorial Army centres and one police station.
The incidents during the three hour strike were mainly of a minor nature and included a fire in a disused house in Bloxwich, Walsall, and a chip pan fire in the Sheldon area of Birmingham.
The head of West Midlands Fire Service, Chief Fire Officer Frank Sheehan, has again offered to meet FBU officials to discuss a settlement to the dispute.
"The disappointment from my perspective is that all this was necessary at all," he said.
"I will be endeavouring to engage with FBU negotiators to discuss how we can resolve this dispute - I want professional firefighters doing the job they are paid to perform so well, rather than on the picket line."
West Midlands Fire Service said the latest proposals included an offer of up to six days additional annual leave and an enhancement of 12.5% on firefighters' hourly rate when working a late split-shift pattern.
The FBU has now notified West Midlands Fire Authority of a third strike date - a five-hour stoppage scheduled for next Monday.