Large plumes of smoke seen above Ramsbottom and parts of Bury are being caused by a controlled burn on moorland.
Concerned residents have called 999 after spotting the signs of a fire coming from moorland near Edenfield Road.
But, Lancashire Fire and Rescue Service has reassured people the blaze was created by a local farmer and is under control.
The smoke can be seen from as far away as Rochdale and the Rossendale valley.
In a tweet, a fire service spokesperson said: "We are aware of a farmer conducting a controlled burn on moorland near Rossendale School, Branford Road, Edenfield.
"A fire engine and crew are in attendance to monitor the situation.
"This will continue until 6pm this evening."
Firefighters have recently been running campaigns to raise awareness of the dangers of moorland fires.
Ahead of a sunny Easter Weekend, Greater Manchester Fire Service Area Manager Paul Duggan warned visitors to the moors to be careful and help avoid a repeat of the devastating 2018 blaze at Winter Hill and Saddleworth.
He said: “The memories of the moorland fires in 2018 remain fresh in the mind of everyone involved, from our firefighters who worked incredibly hard to put the fires out, to the residents who were forced from their homes.
“Moorland and wildfires can be started in a number of ways. Sadly, many fires in the countryside are started deliberately, however, some can break out by people being careless with barbecues, campfires or not disposing of cigarettes properly.
“Our message is strong and clear - never have a barbecue or campfire on the moors or start a fire deliberately wherever you are in the UK.
"Many people think it’s just the flame from a barbecue that sets the moorland on fire, but it’s actually the heat from the disposable barbecue that often sets peat and dry moorland alight.”
