A fire at a building site connected to the new Forth Crossing was started deliberately.
Police said it is just one of a spate of similar incidents in recent weeks.
Detectives are appealing for witnesses after entry was forced to the site and the blaze was started near a pile of industrial rubbish.
The incident happened at 8.40pm on Thursday, July 23 and police are keeping an open mind as to whether the fire is linked to similar incidents in the area in recent weeks.
Detective Sergeant Andrina Cunningham of Corstorphine CID said: “This was a reckless act which threatened the safety of those in the area.
“We’re urging anyone with information to come forward.
“We are also eager to speak to the owner of a black Audi A3 that was seen on the new road from South Queensferry to Winchburgh at the time of the incident, and who may be able to assist with our enquiries.”
Fire Scotland confirmed officers were dispatched to the site, off the new Queensferry Junction, after a call was lodged at 8.47pm.
One appliance was sent to extinguish the blaze at the builder’s yard within 20 minutes.
Anyone with information about the fire or any similar incident is urged to contact Crimestoppers anonymously on 0800 555 111 or call the Police Scotland non-emergency number on 101.