Police are investigating reports that youths were spotted at a historic north-east building, shortly before a huge fire left it in ruins.
The Georgian-era former garden centre, Hillside House, in Portlethen, was completely destroyed by a blaze last Friday.
The incident – which happened just after 10pm – is being treated as wilful by police and fire and rescue investigators.
More than 30 firefighters from seven appliances battled the flames until 4am on Saturday morning, closing the northbound A90 Aberdeen to Stonehaven road in order to tackle it.
A police spokeswoman confirmed they had received “reports of youths frequenting the building in the lead-up to the incident”.
The force now wants to speak to two teenage girls whom they believe might know the identity of the youngsters who were seen in the building prior to the blaze.
The force is also appealing for information following two small fires in the Bourtree area of Portlethen on Tuesday, August 30.
Local sergeant, Neil Grant, said: “I would appeal to anyone with information about any of the incidents in question to contact police as soon as possible.
“We have reason to believe that two teenage girls may have information that could assist in establishing who is responsible for the wilful fire at Hillside House.
“Deliberate fires risk lives and those who set them often have no idea how they will develop or who will be affected.
“A fire is out of control from the moment it begins and – if the worst should happen – flames, heat and smoke can kill.
“Such behaviour will not be tolerated and I can assure the public we will do everything we can to detect those responsible and deal with them appropriately.”
Chairman of the Portlethen and District Community Council, Ron Sharp, added: “I knew there had been youths spotted on the roof of the building during the day.
“Once again, you can put two and two together, but until it is proven you don’t know.
“There are concerns about the incidents happening in Portlethen. There also seems to be more minor crimes that are happening within Portlethen itself. It seems to be increasing.”
Police have urged anyone with information – particularly in relation to the identity of the teenage girls – to contact Police on 101 or Crimestoppers anonymously on 0800 555111.