Some people living in an area with rising Covid-19 cases have “lost their discipline”, claims a council leader.
Rates in Merthyr Tydfil over the past week have overtaken neighbouring Rhondda Cynon Taf (RCT), which was placed in a local lockdown on Thursday.
There were 96 cases per 100,000 residents in Merthyr over the past week, while it now stands at 89 in RCT.
Merthyr council leader Kevin O’Neill said people in the area should “think about others”.
There were 27 new cases recorded in Merthyr on Saturday.
Neigbouring RCT, which is the third most populated county in Wales, saw a further 47 new reported cases of Covid-19.
Across Wales, there have been 212 instances of infection reported, and two more people have died – both in the health authority covering north Wales.
The First Minister Mark Drakeford warned on Friday that officials were keeping a “close watch” on what was happening in Merthyr.
Hospital visits have been suspended in the authority due to mounting cases of infection.
Mr O’Neill said he was “concerned”.
“Because it’s important people still understand we are in a pandemic,” said Mr O’Neill.
“There are certain guiding principles for me, and they are social distancing, wearing a mask, and (hand) hygeine – and people have lost their discipline with that.”
The former senior South Wales Police detective said coronavirus “can move very quickly” in a small population of 60,000.
“We find in certain areas, there are youths congregating, people having parties in their houses and their gardens,” he told BBC Wales.
“Those are areas that concern us.
“Remember, they are putting other people at risk. We talk about putting your grandmother at risk, but most of the people who are getting the infection now are between 20 and 30, so they are their own children at risk, they are putting our schools at risk.”
The council leader said the vast majority of residents in the county borough were sticking to coronavirus rules.
“Those should not be punished by those few who are being silly and irresponsible.
“So I reach out to those who have been silly and irresponsible: Think about others and get back on track.”