Police have said they will use extra stop and search powers in Liverpool city centre.
The Section 60 order – to run until 16:00 BST – is intended “not to stop people going about their lawful business but to deter crime or serious violence”, Merseyside Police said.
The order gives police enhanced powers to search vehicles and seize dangerous items or face coverings.
Merseyside Police has not stated why the order was being brought in, but protests and counter-demonstrations about the use of hotels to house asylum seekers were expected to take place in the city centre.