By Ollie Stone-Lee
BBC News reporter
Two questions seem to be on the lips of Londoners: what is going on and how am I going to get home?
The buses faced an extra burden
Close to the incident at Warren Street, two men at a cafe argued over their versions of events. "No, there WAS a bus," one of them insisted.
Talking on his mobile phone, another man laughed as he told his friend: "You're just looking for a man with wires hanging out of his rucksack."
With tensions high, part of Charing Cross Road had been shut off, apparently because of a suspect package in the street.
As he directed people down side streets, one police officer sighed: "I've been telling them but after all that's gone on today they still want to go through."
Scare or no scare, some Londoners at least were finding it hard to shake off the city's tradition of trying to find the quickest route.
In Trafalgar Square, many tourists seemed unconcerned by the latest news, which was clearly not going to put them off enjoying the warm sunshine.
Mark Johnston, 34, from Cumbria, was starting a holiday with his wife Lynn, daughter Kirby, 8, and four-year-old son Harvey.
The Johnston family were determined to enjoy their holiday
"It's a big place," he said. "You have to be very unlucky and us being scared is what they want."
For others, however, Thursday's minor blasts escalated the fears sparked by the suicide bombings two weeks ago.
London teacher Emma Jones, 23, said: "You're that tiny bit more shaken, aren't you?
"I do think things will go on as normal but it's just that extra thing after two weeks ago where you are going to keep looking around and wondering who is on the Tube with you."
Claire Towerzey faced a long bus wait
The cacophony of sirens running through London's streets did not help ease any lingering worries.
But for many, the chief concern was to find a way home in a transport network reduced to more chaos.
This was not the total Tube shutdown seen after the 7 July bombs and with help from Underground staff, many commuters were able to find trains.
Some stations were closed and the crowds around the bus stops boded badly for those eager to get out of the city centre.
More to come?
Claire Towerzey, 26, told how it had taken her about two hours to get from Green Park to Leicester Square - a distance of no more than two miles. Now she was struggling to board buses full with passengers.
Her friend, Liana Rocco, 39, also from Chingford, had been forced to change buses twice because of road closures.
Police had stopped the buses, checking for unattended bags, she said.
Chris Weeks, an American working in London, said the disruption was something Londoners would probably have to get used to.
"The big thing to put up with is there will be a lot of false alarms and suspect packages, with people trying to be vigilant but equally many people being careless and still leaving their bags unattended," said the 33-year-old.
If he is right, it won't just be the tourists asking for directions as Londoners transport know-how is put to the test.