Some London attractions saw a drop of 10 to 15 per cent in visitor numbers in the three days after the terrorist attack on London Bridge.
A member survey conducted by the Association of Leading Visitor Attractions (ALVA) showed a decline in visits to top London sites after the incident, which resulted in the deaths of 8 people.
The survey also found that some city centre attractions in London and Manchester saw a fall of 6 per cent following the Manchester attack on 22 May.
However, members were able to compare data with the same time last year and conclude that security fears were not the biggest factor in visitor numbers. The weather and programming of temporary exhibitions and one-off events were considered more important.
Attractions also reported that the public have expressed how reassured they are by increased and more visible security measures such as bag searches and clearly identifiable staff at entrances.
Bernard Donoghue, director of the ALVA, commented: "The large number of bars and restaurants participating in Saturday night's #LondonIsOpen event was a strong, reassuring sign of Londoners, and overseas tourists who are here, carrying on with their plans and their lives.
"We also know from talking to overseas visitors that they were reassured by the speed and efficiency of the emergency services' response last Saturday night and that, in their eyes, London is still the safest global capital city."