Bosses at ExxonMobil have apologised after “intense flaring” at a Fife chemical plant sparked alarm in the community.

Many residents took to social media to complain about the flares from the Mossmorran plant near Cowdenbeath, which could be seen for miles on Thursday night.

One Twitter user in Edinburgh described it as being “as bright as streetlights”, despite being 12 miles away.

ExxonMobil said the flaring was part of work to restart operations at the ethylene plant, which has been closed since last August for maintenance work.

A spokesman said: “Yesterday evening we deployed our elevated flare as part of our ongoing work to restart our operations.

“This process is completely safe and controlled, and our team worked to reduce both the size and duration of the flare as quickly as possible.

“We exited the flare later in the evening following the safe completion of our work.

“We apologise to communities for any concern that this may have caused.”

Cowdenbeath councillor Darren Watt tweeted that “the flaring was the most intense I’ve ever seen”.

The company last year announced a £140 million plan to reduce flaring and improve infrastructure at the plant.

The Scottish Environment Protection Agency (Sepa) watchdog launched a formal investigation into unplanned flaring at the Mossmorran plant last April following hundreds of complaints from local residents about a chemical smell and rumbling noise.

In August, Sepa varied the operating permits for ExxonMobil Chemical Limited and Shell UK Limited, which shares the site, requiring them both to address the impacts of flaring and install noise-reducing flare tips.

The Scottish Greens are calling for an inquiry into any impact on the health of local residents.

Mark Ruskell, a Mid Scotland and Fife MSP, said: “The Scottish Government’s lack of action in response to the misery caused by unplanned flaring at Mossmorran is shocking.

“My constituents have been impacted by light, noise and vibration for years, it’s time for a full-scale inquiry into the health impacts on surrounding communities building on the recent review by NHS Fife.

“I’ve repeatedly asked the Environment Secretary to visit those impacted by the flaring but she refuses. My constituents deserve better.

“It’s time for the Scottish Government to lead the discussion on the future of Mossmorran.

“When the plant was opened, climate change was theoretical and the future of North Sea gas was unclear.

“Current regulations are failing to protect people who live next to the plant and they don’t take into account the climate emergency. If the plant has to shut in the years to come then discussions need to start now.”

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.

“Initial data suggests that whilst clearly there was elevated flaring, there was no breach of UK air quality standard.

“We accept that flaring is causing people worry, anxiety and stress. That’s why our firm focus is on addressing the root causes of ‘unacceptable flaring’ and making flaring an exception rather than routine, which is currently not the case.

“We appreciate communities want action, not words – which is why we’re focused on rapid conclusion of regulatory investigation.”