Newcastle has joined Sunderland, Gateshead and South Tyneside on a national government watch list, following a rise in coronavirus cases.
The City Council said 145 new cases had been recorded in the last seven days, or 48 cases per 100,000 people.
Public Health England published the official watchlist on Friday. All four local authorities will now recieve "enhanced support" from the government.
Middlesbrough and Hartlepool also listed as "area of concern".
The number of infections in the region is now increasing by between 1 and 5 percent per day.
The 'enhanced concern' watch list does not mean lockdown measures or further restrictions will be imposed, as in parts of the North West.
However, visits to care homes and hospitals will be suspended or limited and police and council officers will work to enforce the latest coronavirus restrictions.
South Tyneside joined the watch list on Wednesday, while Gateshead was added on Thursday. Both Sunderland and Newcastle were added on Friday.
There were 244 new positive cases recorded in Sunderland between September 1 and September 8, or around 75 cases per 100,000 people, three times higher than the national average.
Gateshead was added on Thursday after cases in the borough more than trebled in the first week of September.
On Thursday, the Director of Public Health said the borough faced "an extremely worrying situation."
Sunderland City Council said that if cases continue to rise, stricter measures could be imposed, including limiting opening hours in pubs, bars and restaurants, the city council said.
As a precaution, care homes across the city have been advised to close to non-essential visits, with the exception of residents receiving end-of life care or with dementia.
The Leader of Sunderland City Council, Councillor Graeme Miller, said he "welcomed" the decision, which represented "support for Sunderland, not restrictions."
We are very close to a local lockdown if there is not a rapid and drastic reduction in the number of cases. The virus is spreading across Sunderland and we need to work together to stop it. It is very simple: The current situation is extremely serious and if more people do not take more responsibility and act more sensibly then we will go back into a lockdown. This is our last chance.
Sunderland City Council has already suspended non-essential visits to care homes and all visits to adult impateint wards in South Tyneside and Sunderland. 'Enhanced support' from the government coud include priority for mobile testing and NHS Test and Trace call centre resources.
All the latest data shows how everybody - of all ages - must continue to stay vigilant, keep two metres apart from people outside of their household as much as possible, continue to wash their hands, get tested and self-isolate if you are showing symptoms. If there are more positive cases then we will look to further actions, such as other cities and towns have seen recently.
Speaking on Thursday, Gillian Gibson urged the city's residents to "stay at home as much as you can. Don't go out every night..."