A large caravan in a paddock used to provide a home for rescued ponies was destroyed by fire.
Crews were called to an address on Plank Lane in Leigh at around 2am on Sunday after loud explosions were heard.
They found the touring caravan, which was around 12ft long, well alight in the field.
Crews from Leigh fire station used hose reels to tackle the flames but the caravan was completely burnt out by the blaze.
No-one was at the site at the time and there were no animals in the paddock.
The cause of the fire is still unclear. Firefighters reported seeing a ruptured LPG cylinder in the caravan but said this could not be the reason the blaze started.
As the caravan was totally gutted Greater Manchester Police (GMP) were asked to attend the scene to see if there were any suspicious circumstances.
The firefighters were at the incident for around 50 minutes.