Thousands have gathered at the sites in London of last Thursday's bomb attacks to honour the dead.
For many the silence was emotional
Crowds gathered at King's Cross, Aldgate, Tavistock Square and Edgware Road to mark a two-minute silence at the flower-strewn memorials that have sprung up.
BBC News website reporters joined the crowds as they paid their respects.
It is not often that King's Cross ever approaches silence. The station is a busy commuter hub, and a nexus for half a dozen Tube lines. The road that runs outside is one of London's busiest arteries.
But on the stroke of noon, a crowd of thousands gathered outside the entrance to the station fell silent.
Buses, trucks, delivery vans and motorbike couriers stopped in their tracks as an eerie hush descended, broken only by the clicking of the camera shutters of press photographers.
In the minutes before, workers streamed out of offices, builders on nearby sites downed tools and a steady stream of tourists, many clutching bouquets, gathered by the impromptu memorial of flowers and flags to pay tribute to the dead.
A few in the crowd were tearful, others put a reassuring arm around a colleague or a friend, while most stared straight ahead.
Despite the sweltering heat, dozens stood in an orderly queue to walk past the memorial and pay their respects to those who lost their lives in the tunnels below.
Thirty minutes before noon the Edgware Road was still buzzing with the sounds of shoppers, workers and four lanes of heavy traffic.
But on Chapel Street, the road which leads to the Tube station - where seven people died last Thursday - things were quiet even before the silence.
Still cordoned off, it is now home to a police witness centre, and scores of flowers and messages which have built up beneath signposts on either side of the road.
Those arriving to observe the official silence positioned themselves around the tributes, some taking pictures on camera phones, others quietly reading messages addressed to Londoners. One reads: "United in grief, united in disgust, united in strength".
The crowd began to build up early, but minutes before noon seemed to swell by hundreds - people packed out Chapel Street, and spread across Edgware Road onto traffic islands as police stopped traffic.
As the noise of cars and buses dropped, a hush fell over the crowd, some hugged, but most continued to stare at the flowers, remembering those killed in the blast.
There were no car horns from angry drivers, all appeared united - determined to stand together in a show of strength.
And then the two minutes were over. Cars and buses started up, people started talking and the crowd quickly dispersed as people went about their business.
But some stay to read over the messages again. A group of Iraqi Muslims have left a message:"All our Mosques are praying for you" and a Buddhist temple has left a note offering sympathy and counselling.
Hundreds of people gathered in the blazing sunshine outside St Pancras parish church, a few yards from the scene of the Tavistock Square bus bomb, still shielded from view by giant tarpaulin screens.
The steps of the church are carpeted in floral tributes from around the world.
"We send a big hug to every Londoner", read the message on one, from Gibraltar.
As mid-day approached, vicar Paul Hawkins appeared on the church steps to say a few words, urging the crowd to remember all those who had died but also to hope that "minds filled with hate may be healed and discover a better way of doing things".
Then as the church clock began to chime mid-day, silence descended.
Some people bowed their heads in prayer. Others just stared ahead, lost in thought. A few choked back tears.
As the two minutes ended Rev Hawkins said a Maori prayer he had chosen for the occasion: "Lead me from death to life, from falsehood to truth; lead me from despair to hope", his words summing up the feelings of many who had gathered there.