The most recent fire broke out at Herdman’s Mill near Sion Mills on Saturday evening.
The NI Fire and Rescue Service said 36 personnel including six appliances along with an aerial appliance attended the incident.
During the evening, firefighters also warned local residents to keep their windows and doors closed and avoid the area in a bid to help support the firefighting operation.
In an update, NIFRS confirmed the blaze was brought under control by their crews on Saturday evening.
While the circumstances behind last night’s blaze have yet to be formally established, it is understood firefighters are currently treating the incident as “deliberate ignition”.
The site has been a subject of repeated arson attacks over recent years, including a significant deliberate blaze started in 2018 which was investigated by police at the time.
One local politician has called for a greater police presence in the area around the mill – which ceased production back in 2004 – to deter political vandals who may target the site.
Speaking to the Belfast Telegraph, DUP politician Keith Kerrigan said: “It was sorted out by the fire service yesterday, but again, it is disappointing to see another fire.
“There have been so many fires which have been lit purposely there over years.
“To have such a picturesque and historic village such as Sion Mills, where there is so much character to it, be again be subjected to vandalism, it is disappointing.
Alderman Keith Kerrigan
“It would be better to have an increase in the police presence, particularly in that area. It would do no harm
“A joint up approach with the PSNI, the community safety wardens, the PCSP and the property owners would be needed to provide adequate and appropriate security.”
Local SDLP MLA Daniel McCrossan said he was concerned by the latest blaze.
“It is disappointing to witness Herdman’s Mill engulfed in flames once again,” he said.
“Considering the building’s precarious state following the previous fire, I worry about the future of these historical structures.”
The PSNI has been contacted.
The Herdman’s Mill building in Sion Mills in Co Tyrone-badly damaged after a previous fire. Photo: TrevorMcBride
Built in 1835 by James George and John Herdman from Belfast, Herdman’s Mill once employed more than 1,000 staff.
It stopped spinning linen in 2004 and the company that owned the mill went into receivership in 2011.
The site was bought by the late lottery winner Margaret Loughrey for £1m in 2014.
When she bought it, the site had been the scene of several fires — a problem that continued after the purchase.
Despite hopes of a much-needed cash investment by Ms Loughrey, relations with the sporting groups who used the facilities in the grounds of the mill quickly soured.
Firefighters battling the blaze at Herman’s Mill, Sion Mills. Photo Credit: NIFRS Facebook
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In September 2014, the lottery winner became embroiled in a row with Sion Mills Cricket Club, founded by the Herdman family in 1864, after locking them out of their pitch on the 60-acre grounds.
In 2016, a court ordered her to hand over part of the complex to the Sion Mills Buildings Preservation Trust because of deterioration.