Health Minister Vaughan Gething said: "In Merthyr Tydfil, the incidence rate is high but the cases appear to be mainly focused around two distinct clusters, linked to a large employer and a pub. Two new, smaller clusters have also been identified.

"In Rhondda Cynon Taf, where local restrictions were introduced on Thursday, we have continued to see both the number of positive cases and the incidence rate increase. It is now the highest in Wales."

Mr Gething said cases in Blaenau Gwent had been linked to pubs and a lack of social distancing but there have also been cases in care home staff and in secondary schools in the area.

Meanwhile, he said a house party in Newport at the end of August had sparked a rise in the city.

Health Minister Vaughan Gething says four more south Wales council areas will be placed under "local restrictions" from 1800 tomorrow to control the spread of coronavirus.

Speaking at the Welsh Government's coronavirus briefing, Mr Gething said "local restrictions" were already in place in Caerphilly borough and Rhondda Cynon Taf to "control a rapid and sharp increase in coronavirus cases in those two areas".

But he said the Welsh Government's "watch list" had grown and now included Bridgend, Blaenau Gwent, Merthyr Tydfil and Newport.

"The seven-day new case rate is now higher than the Welsh rate in Bridgend and Blaenau Gwent.

"We have continued to see an increase in cases in Merthyr Tydfil and Newport, despite the measures introduced by the local authorities in those areas in the past 10 days.

"Because of the developing situation in these four local authority areas, we will be introducing local restrictions in these local authority areas from 6pm tomorrow.

"This will mean a large part of the population of south Wales – and the south Wales valleys – will be subject to local coronavirus restrictions."

Much of the south-east of Wales will be in lockdown from tomorrow after a rise in cases.

This map shows the rate of infection per 100,000 people over the past seven days in each county.

If you live in Newport, Blaenau Gwent, Merthyr Tydfil or Bridgend, here are the rules you will have to follow from 18:00 BST tomorrow.

Six counties in Wales will be under local lockdown measures from tomorrow, after the health minister announced restrictions on four further counties.

Newport, Blaenau Gwent, Merthyr Tydfil and Bridgend county will join Caerphilly and Rhondda Cynon Taf in being locked down from tomorrow.

Blaenau Gwent, Bridgend, Merthyr Tydfil and Newport will be placed under local lockdown from 18:00 BST on Tuesday, Health Minister Vaughan Gething announces.

Health minister Vaughan Gething is about to give the Welsh Government briefing on the pandemic.

You can watch proceedings on BBC One Wales, the BBC iPlayer or via the Welsh Government briefing video link above.

Should other counties be placed under lockdown, certain restrictions will be tightened.

Currently, people cannot leave or enter Caerphilly and Rhondda Cynon Taf without a reasonable excuse and cannot meet indoors with people they do not live with.

In Rhondda Cynon Taf, there is also a 23:00 BST curfew on pubs, clubs and other licensed premises.

You can read more about what you can and can't do in Wales' local lockdowns here.

Speaking earlier today, Mr Gething has said a second Wales-wide lockdown is "not imminent, but always possible".

Cases have been rising across Wales as well as the rest of the UK over recent weeks, and Caerphilly and Rhondda Cynon Taf have already been placed under local lockdowns.

Mr Gething said there was an "increasing tide" of coronavirus cases, mainly in the south-eastern part of Wales.

Image source, Getty Images

Good afternoon and welcome to our coverage of the latest Welsh Government coronavirus briefing.

Health Minister Vaughan Gething is set to begin the press conference at about 12:30 BST.

Here's a list of the main Covid-19 stories this morning:

• A second national lockdown in Wales is "not imminent, but always possible", Mr Gething has said
• Bridgend is facing its "last chance" to prevent a local lockdown, according to the leader of the local council
• A doctor has said she is worried after people accused her of faking a photo following an operation in full PPE