A huge fire has torn through an industrial building after a “big, big explosion”.
Onlookers reported a mushroom cloud and secondary explosion at the scene in Kent as firefighters continued to battle the blaze.
Around 200 people have had to be evacuated while emergency services respond to the incident.
The fire is now under control, the fire service said.
A former Royal Engineer who lives nearby said it reminded him of gas explosions he saw while working with the Army.
Firefighters were called to the scene in Vicarage Lane in Hoo, near Rochester, at 4.30am on Friday, where flames and a plume of black smoke could be seen.
Members of the public were being asked to avoid the area.
Video on social media shows huge flames from the blaze lighting up the night sky, while people posting online talked of an explosion.
The fire has continued to burn and at one point on Friday morning a billowing mushroom cloud of smoke was seen rising up into the sky.
Joe Discipline, who lives nearby, told the PA news agency: “Around 4/4.30am a huge explosion shook the house and windows. I jumped out of bed to see the sky was orange.
“There was then a second explosion, just as big, and that’s when I started to record.”
As the blaze burned, a huge plume of thick black smoke billowed hundreds of feet into the air, prompting the fire service to tell nearby members of the public to close windows and doors.
Gas cylinders were involved in the blaze.
No casualties have yet been reported, the fire service said.
Paul, 60, who chose not to give his second name, lives on St Mary’s Island, across the River Medway from the fire, where he awoke and watched from around 5am.
“I heard cracking and things exploding, so then started to video it – then all of a sudden, boom, it was a big, big explosion,” the sales manager told PA.
“I was thinking, is it going to be like Beirut? At the end of the day, you see the mushroom cloud, then there might have been a secondary explosion which was even bigger, so I was just a little bit worried.
“It was eventful to wake up to, that’s for sure.”
A former Royal Engineer, Paul said the the explosion reminded him of gas explosions he had seen while working with the British Army.
“I was just concerned that nobody was hurt … because of that size of explosion, it’s going to blow a few windows out, that’s for sure,” he added.
Ten fire engines were sent to the scene as firefighters continued to tackle the blaze.
Incident commander, group manager Mark Woodward, said: “The smoke plume may look daunting, but really it’s very similar to what you would get in a house fire.
“The fire is now under control, however we are going to be here for some time.”
Firefighters continue to tackle a large industrial unit fire on Vicarage Lane in #Hoo, near #Rochester this morning – here’s an update from the Incident Commander, directly from the scene of the blaze.
— Kent Fire and Rescue Service (@kentfirerescue) September 4, 2020
A spokesman for Kent Fire and Rescue Service said: “Kent Fire and Rescue Service is at the scene of an industrial building fire on Vicarage Lane in Hoo, near Rochester.
“Ten fire engines and a height vehicle are in attendance, and crews are working to tackle the blaze.
“Firefighters are advising the public to avoid the area while the emergency services deal with the incident.”