Coronavirus laws have been further tightened in Neath Port Talbot, the Vale of Glamorgan and Torfaen in response to a growing spread of cases.
The restrictions came into force at 6pm on Monday and means almost two million people in Wales will now be under some form of tighter restrictions with the majority of South Wales in lockdown.
It comes as economy minister Ken Skates announced £140m of funding to support businesses in areas hit by the new rules.
He told a press conference, "We need to be dynamic in our approach to responding to coronavirus and none of us wants to see a national lockdown if we can avoid it.
"But we know that businesses in containment areas will need extra help."
Sixty million pounds of the funding will be for grants between £1,000 and £1,500 for businesses with a rateable value under £50,000 who have been materially impacted by local lockdown.
A second scheme will support businesses will provide grants for firms to help with its post-coronavirus recovery. £20m of that funding has been ring-fenced for the tourism and hospitality sector.
The latest restrictions, which will apply to everyone living in Neath Port Talbot, Vale of Glamorgan and Torfaen are:
People will not be allowed to enter or leave these areas without a reasonable excuse
People will only be able to meet people they don’t live with outdoors for the time being
Extended households rule will come to an end
How many cases are there in these areas?
In the last week between 18 - 24 September, there were 45 cases confirmed in Torfaen (47.9 per 100,000), 53 in Neath (37 per 100,000) and 46 in the Vale of Glamorgan 34.4 per 100,000.
The First Minister, Mark Drakeford, said: "Following a worrying rise in cases of coronavirus across South Wales, we took action on Friday to introduce local coronavirus restrictions in Llanelli and local restrictions will come into force in our two largest cities– Cardiff and Swansea – tonight.
"We are now taking further action and placing three more areas under local restrictions in South Wales – Neath Port Talbot, Torfaen, and the Vale of Glamorgan – because we are seeing rising rates in these three areas. These areas also share borders with local authority areas where rates are much higher.
“This is not a regional lockdown – this is a series of local restrictions in each local authority area to respond to a specific rise in cases in each area, which have distinct and unique chains of transmission. In some places, such as Caerphilly and Newport, we have seen really positive falls in response and we hope they can begin to be relaxed if they continue."
Local restrictions are already in place in seven other areas of South Wales – Blaenau Gwent, Bridgend, Caerphilly borough, Llanelli in Carmarthenshire, Merthyr Tydfil borough, Rhondda Cynon Taf and Newport.
Restrictions come into force in Cardiff and Swansea at 6pm tonight.Commenting on the latest local lockdowns in South Wales, Welsh Conservative Shadow Minister for Health, Social Care and Sport, Andrew RT Davies said:
“The First Minister might not want it to be described as a 'regional lockdown' but with 2 million people in the south Wales corridor now under some form of restrictions that's unfortunately what it is.
“I once again repeat my calls from last week. I'd like to see a more targeted approach from ministers - local not regional. It is also incumbent on Labour ministers to bring forward urgent financial support for those businesses who will be badly hit by this announcement.
“Ministers should also reconsider the suspension of social bubbles/extended households. The disregard for the mental health of individuals is very concerning and this could be a very difficult period for those living on their own. Please think again.?"