The rate of infection in Sandwell increased to 25.3 new cases per 100,000 people in the week to August 14 as 83 people tested positive, compared to a rate of 22.2 the week before.
Forty of the 83 new cases were in Smethwick.
In the same period the rate of infection in Birmingham almost doubled from 18.2 to 31.5 cases per 100,000 people, giving the city the highest rate in the West Midlands with Sandwell second.
Latest rates of infection in the region:
Average number of new cases per 100,000 people for the seven days to August 14.
Figures show the rate for the seven days to August 14 followed by the equivalent figure for the previous seven days to August 7.
The number of brackets is the number of new cases confirmed in each area in that period.
Data for the most recent three days (August 15-17) has been excluded as it is incomplete and likely to be revised.
Birmingham 31.5 (360), 18.2 (208)
Sandwell 25.3 (83), 22.2 (73)
Wolverhampton 17.1 (45), 11.4 (30)
Walsall 15.4 (44), 7.0 (20)
Telford and Wrekin 14.5 (26), 2.8 (5)
Dudley 4.0 (13), 5.3 (17)
Cannock Chase 3.0 (3), 4.0 (4)
Stafford 2.2 (3), 5.8 (8)
Dr Lisa McNally, Sandwell Council's director of public health, said the increase was at a "concerning level" but said the virus is not spreading at the same rate as the major spike seen in July.
It comes after three Sandwell businesses reported coronavirus outbreaks this month, including one at the huge DPD distribution hub in Oldbury.
Dr McNally told Sandwell Council's emergency committee meeting today: "Our initial surge in cases, which started probably around mid-July, we have managed to bring that down a bit.
"But we are seeing cases increase again - not quite of the same rate before - but still at a level that is concerning and we are going to be monitoring that very carefully."
New data shows Smethwick has once again become the main hotspot in the borough after being the site where the surge of cases in July began. Two Smethwick wards - Soho and Victoria and St Paul's - are of particular concern.
The latest figures show 40 positive cases were confirmed in Smethwick between August 8 and 14.
This equates to 66 cases per 100,000 people - a rate more than double that of the wider borough.
Fifteen cases were confirmed in West Bromwich [18 per 100,000], nine in Tipton [22 per 100,000], nine in Oldbury [17 per 100,000], seven in Rowley Regis [14 per 100,000] and three in Wednesbury .
Around 70 people who attended a barbecue at the Soho Foundry Tavern pub in Smethwick this month were told to isolate after three cases were confirmed there.
The council has not confirmed how many people who were at the pub they have managed to track down.
Dr McNally continued: "At some point recently, Smethwick was caught up by West Bromwich, because Smethwick was originally our main area of concern. It dropped again but it has started to increase for a number of reasons including some significant local outbreaks in the area.
"So Smethwick is once again our key area of concern. We are obviously continuing the intensive community engagement in the area.
More Covid-19 coverage:
"We see West Bromwich, following some intensive work in the area, has fallen significantly and really Smethwick does sit out on its own as a very significant area of concern.
"Specifically in Smethwick, concerns [are] in the Soho & Victoria and St Paul's area."
Dr McNally attributed some of the new cases to the borough's increased testing following the launch of its own test-and-trace system in July.
She added: "Sandwell is doing significantly more testing than the rest of the West Midlands and it is actual above the England average which is a very high level of testing.
"The message is Sandwell's rise to some extent, though not completely, is the function of a rapid increase in testing, which of course is exactly what we should be doing."