Burglars used sledgehammers to smash their way into a garden tool shop and made off with thousands of pounds worth of equipment.
Eight chainsaws, two cut-off saws, two hedgecutters and a leaf-blower were stolen from Horn's Mowerpower on Garstang Road, Preston, on Tuesday night.
Shop manager Chris Black said: "We have CCTV, but all we could see were two shadow figures walking across the show room.
"They knew what they were doing. We suspect they might have been in the shop in the last month or so, but we have that many people in it would be like finding a needle in a haystack."
Armed police were called to the scene after being alerted to the alarm going off at around 8pm.
Burglars had used sledgehammers to break a 3ft hole in the wall of the shop before ransacking the place, stealing £10,000 worth of machinery and causing damage to lawnmowers and other equipment.
A single chainsaw was later recovered by police after it was found abandoned nearby.
Chris said: "The police were exceptionally good and were here within a few minutes of the alarm going off, but unfortunately they just missed them. The thieves were in and out within three minutes.
"It's not just the machines they have taken, but the machines they have damaged as well. Two of the staff ended up being here all night trying to sort stuff out. It has caused us quite a few issues."
A police spokesman added that officers were now looking to trace a car that was seen in area at the time.
They said: "An investigation is still underway."
Anyone with any information about the incident is asked to contact police on 101 quoting the log reference number WB-1710749.