People have been warned they are not allowed to drive from England into Wales for exercise as the two countries move to different lockdown rules.
Rules have been relaxed in England, meaning people can “drive to other destinations”.
First Minister Mark Drakeford said the four Welsh police forces were concerned traffic into Wales would continue to increase as a result of the change.
He criticised the way Boris Johnson made the announcement without making clear it applied to England, and said the UK government was getting it “wrong”.
“I want to be clear – in Wales, it is Welsh law which applies”, he told the daily Welsh Government press conference.
He said travelling to Wales to exercise was not exercising locally.
But he also said two people were already allowed to “interact with each other” at a distance in Wales.
‘What are we supposed to do?’
Spencer Smith lives in Wrexham but works in the Ironbridge Museums in Shropshire.
He said the different measures were confusing: “I work down in Ironbridge, which is about an hour from the border, and my wife still works as a teacher in the Wirral.
“If things do change, then one of the things we’re concerned about is the amount of people we might come in contact with.”
He said he “never” leaves the house in case he becomes ill.
“My wife also worries a huge amount about going out to work – mainly because of the possibility of close contact with others,” he added.
“This is what worries us most, what are we supposed to do?
“Listen to what our government says and stay home or listen to our employers who could easily say that we have to go back to work.
“I tend to think that I’ll stay home because I don’t want to catch this thing. I’m lucky in the fact that I am yet to come close to it, but I do worry about those who must return to the workplace.”
Earlier, the Welsh minister responsible for the coronavirus recovery, Jeremy Miles, said rules “do not permit people to get in their car and drive to destinations in Wales”.
“And that also means people getting in their cars in England,” he added, saying police in Wales “absolutely have the power to fine” people for making non-essential journeys.
But Mr Drakeford said people would not be fined “immediately”, saying he had sympathy with people who did not understand the rules were different.
He said Boris Johnson “could have done more” to explain most of his announcement applied to England only.
Mr Drakeford also said the four police chief constables in Wales had reported “a distinct increase in activity over the bank holiday weekend”.
This followed “many UK national newspapers reported a major easing of the lockdown was on the horizon”, he said.
He said the police had also seen an increase in alcohol-related violence associated with VE Day celebrations and increased traffic across many areas of the road network.
Among businesses allowed to open in England are golf courses.
Llanymynech Golf Club, in Shropshire, sits on the border and has 15 holes in Wales and three in England.
Wales Golf said courses in Wales “must remain closed for now.”
A spokesman said: “As a sport we must work together to resume play responsibly, as and when the relevant government determines it is safe to do so.
“We must ensure that the safety and wellbeing of everyone involved from golfers, to club staff and greenkeepers is maintained at all times.”
South Wales Police Federation chairman, Steve Treharne, said where there had been an easing of regulations in England “people will see the messages and may take up more activities in Wales.”
Driving from England into Wales “still becomes an offence,” he said.
Gwent Police and Crime Commissioner, Jeff Cuthbert, feared the prime minister’s message would cause confusion: “I heard what Boris Johnson said yesterday, whilst we are clear what the rules in Wales are, certainly in the eyes of the public I’m sure what he has said has muddied the water.
“Undoubtedly, because of the strength of the English media there is going to be confusion in the minds of many people.
“It could well be because the prime minister didn’t mention the situation in Wales.”
North Wales Police and Crime Commissioner, Arfon Jones, dubbed differences in English and Welsh measures a “complete mess”.
“How are we supposed to get the message across to people living in England?” he said.
“It’s hard enough ensuring that those living in Wales are aware of the Welsh policy, because so many tune in to television channels from across the border.
“It’s going to be very difficult to get the message across that they should not come to Wales because the measures are different, and that they will be stopped and fined if they break these rules.”
Mr Johnson had made North Wales Police’s work “so much harder, and unnecessarily so,” Mr Jones added.