A person has been confirmed dead and three others rushed to hospital following a serious collision on the A316 near Twickenham Bridge.
The major collision is causing severe delays on west London roads.
A stretch of the M25 has also been closed for hours after two separate lorry fires.
The motorway is shut anti-clockwise in Essex between Junction 28, for Brentwood, and Junction 27, for Epping, following a lorry fire.
A second lorry fire has also shut the M25 between Junction 27, which links to the M11, and Junction 26 near Waltham Abbey, causing travel misery for commuters.
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Live updates
'Not known when lanes will reopen,' National Highways says
National Highways said disruption on the M25 is expected to continue, with no indication yet of when lanes will reopen.
The delays follow a collision between two lorries in queuing traffic between Junction 28 (Brentwood) and Junction 27, which caused one of the vehicles to catch fire.
The incident comes after a separate lorry fire earlier near Waltham Abbey in Essex.
Diversions still in place and roads remain closed
There has been no update from National Rail on when the road closures will be lifted.
The M25 is currently closed anti-clockwise between J28 and J27 due to a collision HGVs, resulting in one catching fire.
There is also a full closure between J27 and J26 due to a separate, unrelated incident.
This has effectively closed the M25 between J28 and J26.
Emergency services are still at the scene.
Update: Fire extinguished and contents of HGV being removed, but road remains closed
“Grab lorries are currently in the the process of removing fire damaged contents from the HGV,” a spokesperson for National Highways has said.
“Once this has been completed the HGV will be recovered. This will then be followed by inspections of the carriageway and infrastructure for any fire-related damage.
“Repairs or clean-up may be needed before the road can reopen. At this stage, no reopening time is available, and the closure is expected to remain ongoing for several further hours.
“If this closure impacts on your planned route, please allow extra journey time. Plan ahead, you may wish to re-route or even delay your journey.”
Lorry destroyed in M25 fire was carrying parcels, photos show
Photos taken on the M25 this morning show one of the burnt out lorry show hundreds of scorched parcels.
As of 9am, there are still delays of over an hour as traffic is backed up for five miles.
Essex Police describe crash on M25 as 'serious'
A spokesman for Essex Police said: “We know this will cause disruption, but this is important work and we’d urge motorists to please find alternative routes.”
Essex County Fire and Rescue Service said it is supporting Essex Police and National Highways at the scene.
A spokesman said: "Motorists are likely to experience delays and are advised to seek alternative routes where possible.
"We thank motorists for their patience and cooperation."
What diversions can I take?
If you’re travelling on the M25 this morning, here’s a list of the diversions you can take to avoid the travel disruption.
- Exit the M62 westbound at J8.
- At the M62 J8 / Charon Way roundabout, take the second exit onto Burtonwood Road southbound.
- At the Burtonwood Road / Westbrook Way roundabout, take the third exit onto Whittle Avenue southbound.
- At the Whittle Avenue / Malvern Close roundabout, take the third exit onto Lingley Green Avenue westbound, passing through four roundabouts.
- At the Lingley Green Avenue / A57 junction, turn right onto the A57 westbound.
- At the A57 / M62 J7 roundabout, take the second exit to re-join the M62 westbound.
Traffic backed up for five miles on the M25
Drivers approaching the M25 near Epping this morning should be aware there are delays of over 60 minutes, with traffic backed up for five miles.
Essex Police and National Highways are on site to try and ease traffic.
In pictures: Lorry destroyed by fire as parts of M25 remain closed
National Highways has released images of the lorry fire between J27 and J28.
Teams are currently working to recover the HGV and its contents.
Delays of over an hour on approach to the M25 in Epping
A spokesperson for National Highways said: “The #M25 remains closed anticlockwise between J27 #Epping & J26 #WalthamAbbey following a HGV fire.
“Specialist recovery is ongoing to recover the HGV & its contents. Current delays of 72 minutes on approach, with 5 miles of congestion.”
Chunk of M25 closed due to to two separate lorry fires
Commuters travel misery this morning as two separate lorry fires have forced a stretch of the M25 to close.
The motorway has been shut anti-clockwise in Essex between Junction 28 for Brentwood and Junction 27 for Epping following a lorry blaze.
A second fire involving another lorry has also closed the M25 between Junction 27, where it meets the M11, and Junction 26 near Waltham Abbey.
Emergency services, including Essex Police, are at the scene.
Delays of up to 10 minutes are expected.