Organisers of Brighton's Gay Pride celebrations are appealing to the record 100,000 crowd expected on Saturday to take security seriously.
The finishing touches are put to a float for Saturday's parade
Discussions have been held with Sussex Police counter-terrorism officers and stewards have been specially briefed.
"Our aim is not to engender panic but to be sensible," said David Harvey, chairman of Brighton and Hove Pride.
"We are saying enjoy yourself, but don't leave bags lying around - they will be taken away."
The carnival parade starts on the sea front at 1100 BST and makes its way to Preston Park, where the festival takes place.
Signs have been erected in the park warning people to keep their belongings with them.
"It is about being sensible and being aware of the risk, and hopefully we will have a very smooth event," said Mr Harvey.
Off-duty Sussex Police officers marched in the parade for the first time in 2004 and this year, about 20 officers and staff are taking part.
"Officers marching in uniform received overwhelming support from the public and it was obvious that our presence was appreciated by the Lesbian, Gay, Bisexual and Transgender (LGBT) community," said Sgt Mark Andrews.
"We are showing that not only do officers police the LGBT community but they are also part of that community themselves."
Mr Harvey said the Pride festival was popular beyond the gay community.
"Last year, Brighton University researched who was in Preston Park and found that, of Brighton residents, about half were from the heterosexual community.
"Of visitors, which is a significant number of people from London and further afield, about a third are heterosexual.
"It is a sign of the times that people party with their friends and sexuality is a bit of a non-issue."