On Sunday, government figures showed nine new cases for the city in 24 hours, and on August 10, seven new cases.
The last time Bristol’s cases exceeded 11 was on July 3, when more than 500 were identified in a single day as the government updated the way it was recording data.
Two of Bristol’s neighboring districts also recorded increases.
Bath and North East Somerset saw an increase of three, bringing its total to 371.
While four more cases have been recorded in South Gloucestershire, which now has 789 cases.
North Somerset was the only area not to report an increase, its total remaining at 929.
Nationally, 1,182 new cases were registered today, bringing the UK total to 322,280.
None of Bristol’s hospital trusts have recorded coronavirus-related deaths since the start of July.
However, four deaths were recorded in nursing homes in and around Bristol in the first two weeks of August.
Across the UK there were 41,403 deaths after a daily increase of 6.
Bristol’s new warning
The figures come just a day after Bristol city leaders issued their first joint warning since the lockdown measures were relaxed.
Christina Gray, Bristol’s director of public health, and Deputy Mayor Asher Craig urged people not to participate in mass gatherings – including protests and group marches.
The statement reads: ‘We have seen a slight but noticeable increase in the number of COVID-19 cases in Bristol over the past seven days and would like to remind citizens of current government guidelines to help prevent further cases .