The Gortin Road in Omagh is closed at the junction with Killybrack Road due to a gas leak.
Police say a number of homes and businesses are being evacuated.
The public is being advised to avoid the area while emergency services deal with the incident.
Evolve the gas distribution network operator for the area says there was damage caused by a third-party contractor.
Find the full statement below:
We can confirm that a gas main has been damaged by a third-party contractor. The incident is localised to the immediate area, with gas supplies to homes and businesses across the town remaining unaffected at this time.
“Following a technical assessment, our engineers established a 15-metre safety exclusion zone, within which no properties are located. The Northern Ireland Fire & Rescue Service, as the lead emergency response authority, has implemented a wider 100-metre exclusion zone in line with its operational procedures, resulting in the precautionary evacuation of nearby homes and businesses.
“We fully appreciate the disruption this has caused, particularly for those who have had to leave their homes or businesses. We continue to work closely with NIFRS and the relevant authorities to ensure the incident is resolved, with the safety of the public and our colleagues remaining our absolute priority
