An environmental watchdog is monitoring air quality at a Fife chemical plant as unplanned flaring continues.
The flaring began on Easter Sunday at the ExxonMobil Chemical Ltd facility at Mossmorran.
Residents have complained of a chemical smell and rumbling noise that can be heard from several miles away.
The Scottish Environment Protection Agency (Sepa) said air quality monitoring would continue but so far had shown no cause for concern.
ExxonMobil said the flaring was caused by a fault in a section of cable that resulted in the plant moving to fail-safe mode which was standard procedure.
The latest incident comes after Sepa served ExxonMobil Chemical Ltd and Shell UK Limited with final warning letters last year following unplanned flaring at the Mossmorran complex in June 2017.
'Flaring to continue'
Terry A'Hearn, Sepa's chief executive, said: "On a weekend with beautiful weather here in Scotland the people of this community should be free to enjoy it so we're extremely disappointed that they've been inconvenienced by this incident.
"We're working with Exxon to make sure that the flaring is reduced as quickly as possible and we'll be measuring the impact to see what the effect has been.
"We'll also be looking at what has caused this incident and if any further action is needed the community can be assured that we will be taking it as your regulator."
Sepa said ExxonMobil Chemical Ltd had advised it that flaring was likely to continue over the coming days.
Local people took to social media to complain about the latest incident.
One woman tweeted: "I'm extremely concerned about the flaring from #Mossmorran. The noise last night after 10pm was horrendous, it was like being behind an aeroplane with its back burners on".
Another wrote: "Will this be another night of #Mossmorran constantly rumbling on like a jet engine taking off? Chemical smell this morning too."
'Established industry practice'
Stuart Neill, external affairs manager for the ExxonMobil Fife ethylene plant, said: "We absolutely understand the disruption that the current unplanned flaring is having on communities in the area.
"Our team are working round the clock to bring the plant back to normal operations, a process which will take a few days to safely complete. During this time we will, regrettably, need to continue to flare.
"The unplanned flaring was caused by a fault in a section of cable that resulted in the plant being moved to fail-safe mode as per established operational procedure."
He added: "Flaring is an established industry practice, essentially producing water and CO2 from the combustion of Ethylene and steam.
"We are doing everything possible to minimise both the flaring and the timescales to resolve this unplanned event."