49 outdoor fires were started deliberately over the past two months, according to Cambridgeshire Fire & Rescue Service whose crews are "spending significant time at incidents that could be avoided".

The service said that, so far in June, they have seen 82 fires in the open, compared with 67 last year. Of those fires, 20 were started deliberately - compared to 24 for the same period last year.

And, in May, crews attended 85 fires in the open compared with 99 in May last year. Of those, 29 were deliberately ignited (compared to 33 last May).

A Cambs Fire spokesperson said: "The warmer weather often sees our crews called to fires in the open, which can spread very quickly due to the dry conditions. Many of these fires are started deliberately. 

"We do tend to see an increase in calls to fires during spells of warm weather, which results in our crews spending significant time at incidents that could be avoided.

"This is concerning as the crews are committed and cannot respond to other emergencies, but also for local residents being put at risk because of deliberate fire setting.

"Any fire, not matter how small, can quickly get out of control and spread, endangering those around and the fire crews that come to tackle it."

Among the recent fires in the open was a blaze at a nature reserve in Peterborough this month, which was started deliberately.

"This tied up our crews for several hours and saw smoke spread across the city, closing the A47 for some time," added the spokesperson.

"This shows how quickly these fires can spread and the impact they have, so we urge people to not start fires intentionally."

The fire service has since issued tips for helping to prevent these fires from happening.

"Parents can speak with their children and ensure they know the risks and dangers of fire, especially with half term approaching at the end of the month.

"Also, making sure lighters and matches are kept well out of reach of children, as well as making sure they stay clear of disused or derelict buildings, can also make a big difference.

"We do urge residents to make sure they call 999 to report a fire, even if you see a small sign of smoke so our crews can respond quickly and stop it spreading."