A police investigation has been launched after 500 tonnes of straw was set alight in a suspected arson attack on a farm.
The blaze was started on land in Withersfield, Cambridgeshire at around 6.15pm on Tuesday (September 19).
No one was hurt during the fire and it is not thought to have spread.
A Suffolk Police spokesman said: "We were called at 6.45pm on Tuesday to reports of a hay stack on fire off Rose Hill in Withersfield.
"A straw stack reported as 500 tonnes of straw was set alight. The incident has been treated as arson.
"Any witnesses with any information should contact Haverhill Police on 101 CAD 386 September 19."
A Facebook post claimed there were around seven individuals seen moments before the fire started.
It read: "A group of around seven young lads on push bikes (approx age 12-14 years old) were seen by a few dog walkers in this area between 6pm and 6.15pm today (Tuesday 19th September 2017).
"The fire was reported at 6.20pm, meaning these lads could have witnessed who started the fire.
"These lads were seen heading up to the hay bales on push bikes and were witnessed by a few people during these time frames.
"If anyone has information please inform the police."
The incident follows a call from the Country Land and Business Association (CLA) which urged farmers to take precautionary measures during harvest and beyond in order to reduce their chances of being a victim of arsonists.
CLA East Regional Director Ben Underwood said: “Deliberate straw stack fires destroy important material used in arable and livestock farming, as well as a valuable renewable energy source – it’s not just a by-product.
“These fires can spread rapidly threatening buildings, livestock, machinery, and potentially human lives.
“Deliberate fire setting causes untold problems and the people involved do not give any thought to the consequences."
Worrying reports of straw stack fires in recent days. Previous CLA advice on this is still relevant t.co/Y7edQfVlPv— CLA East (@CLAEast)
Recommendations offered to farmers include positioning stacks away from public roads and visible places, and splitting large stacks into smaller ones with a 10-metre gap down the middle so that if a fire occurs there is a chance to move unburnt straw away.
Farmers are also being advised to avoid stacking bales near buildings with livestock inside so if a fire starts animals are not endangered, and to remove hay and straw from the field as soon as possible – if it has to be left overnight consideration should be given to blocking access routes to it.