"One hospital, near Warren St station, has started its emergency plan.
Sosiane Mohellavi, 35, was travelling from Oxford Circus to Walthamstow when she was evacuated from a train at Warren Street.
"I was in the carriage and we smelt smoke - it was like something was burning.
"Everyone was panicked and people were screaming. We had to pull the alarm. I am still shaking."
But a BBC reporter outside Warren St station said there was no sign of smoke outside. (Pictures from Warren Street)
And there is now a reported incident of a problem on a bus at Hackney.
[ Update 13:45]
It's the Hammersmith & City line of Shepherds Bush. Reports of detonators going off which suggest failed bombs?
[ Update 13:50]
Ok, they're saying "not as serious" as two weeks ago, but the WHOLE tube system has just been suspended. No tubes people! Incident also on a no. 26 bus in Hackney now being reported.
There's definetely been some sort of explosion on a train somewhere.
[ Update 13:55]
'Explosions' appear to be dummy detonators. No casualties reported. It's NOT a major incident, but windows WERE blown out on the No. 26 bus.
I'm guessing it's someone proving that detonators (with no explosives) still get past the sniffer dogs, and they're doing it to show that panic and disruption can still be caused.
Arseholes. Whoever you are.
[ Update 14:10]
It would appear to be people just trying to cause panic. Only the Northern, Victoria and H&C lines are shut, the whole system is NOT shut. (see the Tube's website)
A rucksack with a "firework like" explosion has happened just before Warren Street. People panicked and rushed out when the train came into the station.
Similar device on the No.26 bus in Hackey which has taken out the windows, and reports of one minor casualty.
Stay calm ...
[Update - 14.30]
Police statment from Commissioner Sir Ian Blair. Read the full transcript here
[15.20 - Update from Annie]
Wow, thanks for holding the fort Geoff, I was busy stuffing my face in Gourmet Burger Kitchen when this all kicked off. Amazingly I would have been at Shepherds Bush around that time, and am still thinking of heading off there this afternoon, as I'm currently updating from an Internet Cafe. Apparently according to the BBC Tony Blair is about to make a statement any time now so listen to the radio or watch TV.
[15.44 - Update from Annie]
The BBC are showing pictures of armed police arresting a man outside the gates of Tony Blair's Downing Street offices. Keep an eye on the BBC reporter's log for latest updates.
[19.00 - Update from Annie - Some pictures of the day]
I only live a few miles from Shepherd's Bush in West London. So I thought I would still go to Shepherd's Bush as planned, anyway just to see how far I could get. Not very far as it turned out but took some pictures on the way.
Outside my station, The Evening Standards with their new alarming headlines were coming off the van.
I took the District Line to Hammersmith as planned and normally, I'd be able to change there and get onto the Hammersmith & City Line to Shepherds Bush. Going past my old home station of Kew Gardens, I saw a policeman, which is probably the first time I'd ever seen a cop there.
At Hammersmith, not surprisingly the station was crawling with police and as I arrived lots of people were crowding around a noticeboard as one of the tube staff was writing down the latest closures and travel updates.
Leaving Hammersmith, I saw that Shepherd's Bush Road had been closed off, so short of walking there, I thought I may as well head back home.
Outside the entrance to the Hammersmith and City Line there was a pretty simple sign
By the time I got back to Hammersmith, the handwritten sign had filled the board and the Piccadilly Line had been completely suspended along with a number of other sections of lines. As usual people were milling around looking a bit confused and pissed off that their journeys home would be delayed, but no one was wringing their hands and fleeing the streets.
So I headed home on the District Line and saw something which kind of sums up the last few days worth of posts. On Tuesday I was happily posting about Harry Potter sightings on the tube and now it's bombs again.
But thankfully no one died (even though the Police say they meant to kill), no one was seriously injured and the police have managed to gain a lot of forensic evidence which hopefully might catch these nutters. In the meantime life will go on as normal and we'll continue to travel public transport and this will just make people even more vigilant and even more determinded not to be afraid.
As Ken Livingstone said, at today's press conference; "I'd like to start by congratulating the police and the emergency service and the tube and bus staff who have responded with even more remarkable speed. For those of you who watched this unfold through the television coverage the speed of the response I think was absolutely amazing. And the other factor is that the underground staff and the bus staff have managed to get the vast bulk of the system back up and running and have clearly shown their determination not to have our life disrupted more than is absolutely necessary by these incidents..........
It is not surprising that we have had another attempt to take life in London so rapidly after the first. Those people whose memories stretch back to the terrorist campaigns in the Seventies and Eighties and early Nineties will remember there were very often horrifying bombings in London often only weeks apart and we got through that and we will get through this."