Heatwave temperatures and tinderbox conditions continue to spark wildfires across the region but investigators are probing whether some have more sinister origins.
Arsonists are believed to be behind at least some of the fires that have swept fields and open land, putting at the risk the public and firefighters stretched to breaking point.
Norfolk Police have confirmed they were called to a number of reports of fires over the weekend that now being investigated as arson. Amongst them are another fire on Mousehold Heath in Norwich and a blaze at North Walsham.
Dramatic images of separate straw bales on fire between Ranworth and South Walsham on Sunday were captured by eye-witness Ian Thompson, who called the fire service and tried to put the fires out before they got out of hand.
He said: 'I can't believe there was any way it could not have been started deliberately.'
A Norfolk Constabulary spokesperson said: 'Arson is an extremely serious crime, which not only causes significant damage, but can also threaten lives, especially in the tinder dry conditions we're experiencing at the moment.
'Officers are currently investigating a number of incidents in rural locations across the county as deliberate and fortunately no one has been injured as a result of them. I would urge residents, in particular farm owners, to be vigilant and report any suspicious behaviour.'
Since the start of 2018 there had been 261 open fires across Norfolk up to the weekend and a hectic two-day period saw dozens more call-outs. More than 70 of them believed to have been deliberate.
Garry Collins, Head of Protection and Prevention at Norfolk Fire and Rescue Service, said: 'Arson costs lives. They are putting lives at risk and stretching our resources and we may well be needed elsewhere.'
Many of the fires started during the current hot weather have been classed as deliberate although not all have been reckless or malicious.
Mr Collins said: 'Open fires can quickly spread and endanger life. Some of these incidents were not intentional but if you are somewhere and a fire starts, it is hugely important that you call 999.'
Pressure on the fire service showed no sign of abating yesterday with crews called to tackle a large fire in woodland off Haveringland Road in Felthorpe, and three fires that broke out in just over an hour near Aldeby, near Beccles.
There were also open fires at Holt, Hockwold Cum Wilton, Heacham, Great Massingham, at Lakenham and Sprowston and at Barnham Cross Common, near Thetford.
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