Four fire crews battled a suspicious blaze in the city centre during Thursday afternoon.
AdvertisementA former skate park in School Street, off Bow Lane, is believed to have been set alight.
Crews from Preston, Fulwood and Penwortham attended and tackled the flames in an area measuring 50 metres by 30 metres.
Explosions were reported coming from the fire at around 3.57pm. The fire is within what used to be the Format photography company unit.