Organisers of the London Marathon have urged people to come out and support Sunday's race in the wake of the devastating fatal bombings at the Boston Marathon.
Three people were killed and over 180 injured, many seriously, after two bombs were detonated as runners made their way towards the finish line in the US city's race on Monday.
In response, organisers of the London Marathon reviewed security measures for Sunday's race in the British capital before confirming that the event would go ahead as scheduled.
A 30-second period of silence will be held before the start of the race in memory of the victims of the Boston attacks, while organisers are also encouraging competitors to wear black ribbons.
As yet, there have been no high-profile withdrawals from the event by elite runners, with British Olympic star Mo Farah among the top-level athletes scheduled to compete, although he is only running half the race.
"We are confident we are taking all reasonable and appropriate measures to ensure the race is safe for spectators, for runners and for the people of London," said London Marathon chief executive Nick Bitel.
"It is a great occasion, the London Marathon, and I know people will want to send a message of support by coming out and supporting the runners on the day."
However, former London Marathon champion Paula Radcliffe said that she would have doubts about taking her family to this year's event.
"I have every confidence in the London Marathon community and the Metropolitan Police that they won't let it go ahead unless they have done everything possible," the women's marathon world record-holder told BBC radio.
"But it's still 26 miles... It's going to be hard. It's going to rely on people being vigilant and aware of what is going on around them as well.
"I think first and foremost, as a mother, I'd think more about having family at the finish area.
"You put yourself there at your own risk but putting family in that situation is something people are going to have to come to terms with and conquer."
London witnessed a major security operation on its streets on Wednesday, with 4,000 police officers deployed for the funeral procession of former prime minister Margaret Thatcher.