Officials have responded to the "unacceptable flaring" at Mossmorran gas plant in Fife last week, with flames said to have been visible from up to ten miles away.
Edinburgh Live previously reported how the skies above the ExxonMobil Fife Ethylene Plant were lit up red and orange, with some saying it is the most intense event they have seen so far.
Many people shared dramatic photos of the scene, which was described as "Mordor" and now an alarming clip has emerged on social media.
On Thursday night Jake Hyslop shared the video from near the plant, writing: "Mossmorran apparently on fire (buildings not flare)."
The latest flaring is part of a process to restart the plant, which temporarily closed last year, and led to a high volume of calls to the environmental watchdog SEPA.
The Scottish Environment Protection Agency (SEPA) has since issued a statement, insisting that initial data suggested there was "no breach of UK Air Quality Standard".
Chris Dailly, Sepa's head of environmental performance, said: "Thursday’s unplanned flaring during ExxonMobil Chemical’s restart at Mossmorran is a real reminder of why short and medium term solutions are critical to addressing the root causes of unacceptable flaring.
“While elevated flaring is a possibility during restart it was not expected last night. Once again we heard clearly and powerfully the very real concerns and frustrations of local communities.
“We think it’s important to be clear on the causes of the flaring in the final stage of this restart. We know people also want information on our monitoring. Since last year SEPA has had monitoring points around the site.
"Initial data suggests that whilst clearly there was elevated flaring, there was no breach of UK Air Quality Standard. We publish the data we collect on a weekly basis and now some 28 detailed reports are available."
He added that SEPA is aware of the "worry, anxiety and stress" that "unacceptable flaring" causes and are working with operators ExxonMobil to reduce the impact through planning and design.
The plant receives hydrocarbons extracted from the North Sea, using a process called flaring to remove harmful gases. While the technique is legal, operators are required to minimise the impact.
