Passengers have described the moment a carriage filled with thick smoke after a train 'hit an object on the tracks' and caught fire this evening.

Commuter Lauren Rule said she was struggling to breathe and customers were forced to pull the emergency cord and stop the train near Northfleet.

She wrote on Facebook: "We got to just outside Northfleet and the carriage filled with thick smoke and you could smell fire.

"We had to pull the emergency release and jump down to the tracks to get off.

"We were struggling to breathe because the carriage was filled with smoke."

"We were mid way up the train, saw smoke outside, then sparks, and before we knew it smoke begin to fill the carriage" - Keeley Richards

Other passengers further down the train reported 'loads of smoke and sparks' coming from the side of the train, followed by an announcement from the driver that it had collided with an object on the line.

Passenger Keeley Richards was travelling with her family and also reported the carriage filling with smoke, leaving the children terrified.

She told KentOnline: "It all happened very quickly. We were mid way up the train, saw smoke outside, then sparks, and before we knew it smoke began to fill the carriage.

"Members of the public pulled emergency cords, and ushered us up the train.

"They tried to open the doors but couldn't. Eventually they got them open and helped lift us and our children off as some of them were hysterical.

"I don't think there was any announcements but it was crazy on there!

"We were off the train quickly and fire services arrived as we got off. I hope the driver was ok.

"We saw smoke and big sparks, no flames that I saw but there was so much smoke there was obviously a fire.

"Fire crews said they thought brakes caught fire but I don't know for sure what happened."

Ms Richards praised the emergency services and fellow passengers for their reaction to the incident.

Kent Fire and Rescue told KentOnline they were called at about 7pm, sending six fire engines, a water carrier and a foam unit to the scene, initially fearing a more serious incident.

But after inspecting the train and assessing passengers, the crews were stood down.

Any fire that did start appears to have gone out very quickly and no injuries have been reported.

Kent Fire and Rescue have reported it as a false alarm with good intent.

Another passenger said: "Basically loads of smoke and sparks came out of the side of the train.

"The driver said it hit something on the track."

Despite the driver's announcement, a Southeastern spokesman told KentOnline the cause of the fire was still under investigation.

He said the company could not rule out a train fault - possibly a defective brake shoe - or even vandalism, causing damage to the train.

Eyewitnesses told KentOnline they could not see any obvious damage to the carriages after getting off the train.

The said people left the service in a calm, orderly manner, despite having to jump to the tracks in some cases.

However, other passengers have hit out at the train company for failing to manage the evacuation.

Hayley Wells said: "Passengers... had no information on what to do. Kids crying, doors just opened, people on the track."

All services through the station were suspended but are now running, albeit with delays.

At about 8.30pm Southeastern said: "The incident at Northfleet is now clear and train services are running between Dartford and Gillingham but with some delays and amendments."

The exact cause of the fire and smoke is not yet clear, and engineers are investigating.