More than 30 firefighters in Lowestoft had to put out fires at a disused factory site in Lowestoft.
Suffolk Police say investigations are continuing after two fires were started on parts of the empty former Jeld Wen and Bolton and Paul timber factory site on Waveney Road.
It took seven fire crews more than two hours on Saturday night at around 8 oclock (25th January) to tackle blazes in two areas of the site that have been empty for the last 15 years - and bring them under control.
No-one was hurt in the incident.
An investigation is underway and anyone who saw any suspicious activity or has knowledge of who was responsible should contact Lowestoft police, quoting crime number 37/4556/25.