Anti-lockdown campaigners forced a vaccination centre to close after a protest in Brighton.
Footage on social media showed protestors led by Piers Corbyn surrounding a vaccination bus on the sea front and cheering as it drove off.
Corbyn, the brother of former Labour leader Jeremy Corbyn, has been a vocal critic of the government’s lockdown and vaccine programme.
The local health authority said vaccinations on Hove Lawns were postponed on Sunday “to ensure that everyone is able to receive their vaccine safely and without any pressure put upon them”.
It said its staff “experienced disruption during the anti-lockdown measures protest in the city”.
Vaccinations are still available elsewhere in the city.
Brighton and Hove council leader Phelim Mac Cafferty, said: “As we have rising cases, it is incredibly disappointing to see the irresponsible actions of a few putting in danger the many.
“We reaffirm our city’s need to keep our population safe and we won’t be deterred from our important vaccination programme by the acts of cowards spreading misinformation.
“We encourage everyone to take up both vaccinations at the earliest point they can. Our proud tradition as a city is that we work against adversity and we won’t be deterred from fighting the pandemic together.”
Brighton and Hove has experienced a sharp rise in coronavirus infections in recent weeks, with the area recording 423.5 cases per 100,000 people for the seven days to July 5, according to data analysis by the PA news agency.
A walk-in vaccination service will continue to be available at Brighton Racecourse from 2.30pm to 6.30pm and will be open to all on Monday.
There will also be walk-in services every day next week, including at the Brighton Centre from 8.30am on Monday.