A massive plume of smoke from the stack at Stanlow oil refinery near Ellesmere Port could be seen over a wide area following a power cut this morning.
Alarms sounding in the area exacerbated worries, along with the fact that the phone numbers for the Essar refinery were not working, said Cheshire Live.
Scottish Power said the power cut affected large areas of west Cheshire, including Stanlow, Frodsham, Helsby, and Ince.
A Cheshire Fire and Rescue Service press office spokesperson said emergency services were alerted at 10.37am.
They said the flames related to "chimney flaring" believed to have been sparked by a power cut, adding: "It is nothing to be concerned about."
The utilities company said supplies were restored by noon.
People took to social media to tweet pictures of the smoke coming from the refinery.
No-one was available for comment from the Essar refinery, but it has previously said that flaring is part of the "routine safety system" at the plant.
Cheshire Fire Service said that flaring would continue at Stanlow throughout the day, but there was no cause for alarm.
MP Justin Madders said: "I have spoken to Essar, it’s a safety response relating to the loss of power to the site."
