At 11.27pm on Friday (24) two crews from St Neots were called to a fire on Musgrave Way in St Neots.
Firefighters arrived to find a fire in a garden that was spreading to two houses. They extinguished the fire using a hose reel and cleared the smoke using a positive pressure ventilation fan.
The crews returned to their station by 12.25am.
The cause of the fire was accidental, due to discarded smoking materials.
A fire service spokesman said: “It is important to ensure that any smoking materials are extinguished fully and disposed of thoroughly. Any fire, even from a discarded cigarette, can spread quickly if left unsupervised and not extinguished properly.”