Fire crews from Aberdeen were called out on two separate occasions to deal with tipper truck that had caught fire on the AWPR construction site.
The incidents, both at the stretch of the new road between Kingswells and Westhill, occurred between 10.15pm and 10.50pm on Tuesday night.
A spokesman from Scottish Fire and Rescue said: “We received calls at 22.19 and 22.48 to attend two tipper trucks that were on fire on the construction site of the AWPR.
“Two crews from North Anderson Drive attended the first truck and two crews, one from central and another from Dyce attended the second.
“Police were also in attendance.”
A police spokesman last night said: “Inquiries are on-going and we are currently still in attendance after we were advised of two low-loaders being on fire.”
A Transport Scotland spokesman said: “The project contractor, Aberdeen Roads Limited, is responsible for the safety and security of the AWPR/B-T site. We are aware of a number of incidents that occurred last night [Tuesday]. Police Scotland is currently investigating this and therefore it would be inappropriate to comment further.
“In the meantime, ARL will review their existing site security measures.”