Thames Valley Police is appealing for witnesses following an arson attack in Banbury.
Emergency services were called to Bretch Hill Farm in Banbury at 1.41pm to reports that a derelict building on the grounds was on fire.
It is now believed that the fire was started deliberately and four boys were seen running away from the scene shortly after the fire took hold.
The blaze caused damage to adjacent farm buildings and a number of trees were also damaged.
Houses in the nearby area had to be evacuated while Oxfordshire Fire & Rescue Service dealt with the blaze.
Investigating officer PC Dominic Watson based at Banbury police station, said: “I am appealing for anybody who witnessed this incident or believes they know who the offenders are to make contact with police.
“This was a large and aggressive fire which needed police, fire and ambulance attendance.
“The impact on local residents and landowners was considerable, but thankfully, nobody was injured as a result of the blaze.
“At this early stage of our investigation, I believe the suspects to be local to the Bretch Hill area and have local knowledge.
“I am appealing to anybody with any information, no matter how insignificant this may seem, to contact the 24-hour non-emergency number 101, quoting reference number 43190309375.
“I am appealing to any parents in the local area, do you know where your children were this afternoon? This was an intentional and dangerous act that has impacted the local environment, land owner and the local community.
“It was also resource intensive for all three emergency services.
“If you do not wish to speak directly with police, you can make a report online, or call the independent charity Crimestoppers anonymously on 0800 555 111.