Ash was said to be falling from the sky and people were evacuated from their homes following a huge field fire near the M25.
Huge clouds of smoke could be seen for miles rising from the Beechenlea Lane area of Swanley during this afternoon's rush hour.
Dramatic aerial pictures showed the flames coming from a field near Junction 3 of the motorway.
The fire service said it was working in "difficult conditions" to battle the corn field fire - which destroyed an area the size of 22 football pitches - due to the changing wind direction.
One person posted on social media to say they could see the plumes from Brentwood in Essex.
Reporter Katie May Nelson, who is at the scene, said: "There’s at least four fire trucks from London Fire Brigade and Kent Fire and Rescue.
"People living near The Olympic club - including me - have been evacuated by the police as there is ash falling from the sky and they’re turning cars away."
Kent Fire and Rescue Service was called to the blaze at the standing corn field in Hextable, Swanley at about 4.30pm and remain at the scene this evening.
A statement shared shortly before 7pm said that 12 fire engines and a number of support vehicles have been sent to the blaze.
"Firefighters are working in difficult conditions due to the variable wind direction causing the fire spread in different directions," it says.
"People living in the area are being asked to close windows and doors due to the large amount of smoke being generated. Please share with anyone you know that is not online.
"The size of the fire is believed to be around 12 acres, the equivalent of six football pitches.
"There are no reported injuries and the cause isn't known."
Residents were evacuated at about 5.30pm but were told they could return to their homes at about 6.15pm.
By 8pm firefighters were said to be making good progress, but two fire engines remained at the scene.
The estimated area of damage to the crop is 34 acres - around the same size as 22 football pitches.
The blaze was brought fully under control at around 9pm.