Police officers are facing "greater hostility" from the public when enforcing Covid rules, the head of the South Wales Police Federation has said.
Steve Treharne said officers were dealing with "significant problems" of people congregating in public spaces.
It follows "numerous reports" of crowds at beauty spots over the weekend, which led to the closure of car parks and fines being issued.
Covid rules mean you should only leave home for essential reasons or exercise.
Mr Treharne told BBC Radio Wales: "It's incredibly frustrating for our officers and, I dare say, the community at large.
"We understand people are incredibly frustrated these restrictions have been in place for a long while now, however, the rules are quite clear on this, that people shouldn't be travelling to take exercise.
"I don't think the situation is being helped with the circumstances around off-licences being allowed to open, so we've got people congregating," he added.
"The off-licences are open, people are purchasing alcohol and of course that brings us significant problems, and our officers are now facing greater hostility from members of the public and it's not really fair.
"Our officers don't draft the legislation, they've got a job to do and they can only enforce the legislation that's there."
At Monday's Welsh Government coronavirus briefing, First Minister Mark Drakeford called for "responsible" behaviour as more people head outside.
He said: "I understand that over the weekend, when the weather was beautiful and people have spent the long winter months confined at home, people wanted to enjoy the fresh air, but it's still a matter of doing that in a way that's responsible and within the rules.
"When I was walking in Cardiff yesterday, there were lots of people out but they were still behaving in a way that was respectful to one another, and that's what we need to see continuing."
Wales' Chief Medical Officer Frank Atherton warned that "coronavirus has not gone away".
"People have been cooped up over the winter. When the sun comes out, we want to be out and about," he told BBC Radio Wales Breakfast.
"Community rates have come right down, but we've been here before.
"We had very low rates last summer, and we've seen how quickly it has taken off. There is still a risk that the virus could come back."
As weather improved over the weekend, car parks were closed across several beaches in Swansea at the request of police.
Carrie Townsend Jones, a community councillor from Mumbles warned people not to travel from far away to visit the area.
She said: "I do understand it's very difficult for people, particularly if they don't have outdoor space, you know they're looking out and the weather's lovely and of course they're desperate to get out, but there are lots of other places where people can walk that are local to where they live."