Welsh holidays could be in jeopardy, as the First Minister has threatened to stop the easing of the lockdown.
First Minister Mark Drakeford said he would stop loosening restrictions if there continues to be mass gatherings.
In Wales the current lockdown guidance restricts non-essential travel to five miles and even then people must observe social distancing of two metres.
People from England are not allowed to cross the border and holidays are not permitted.
But it was hoped that these restrictions would soon be eased, allowing tourism in Wales - reports Wales Online.
Last week Mr Drakeford said the "stay local" five-mile restriction is due to be lifted on July 6 and from July 13, he said people are likely to be able to go on holidays:
- to a static caravan with its own kitchen and toilet
- to a rented cottage
to a hotel that has turned itself into self-contained accommodation.
However after hundreds of young people descended on the Welsh beach Ogmore-by-Sea and got into violent clashes, the First Minister has threatened to halt the lockdown easing.
Writing on Twitter, First Minister Mark Drakeford said: "We will not be able to continue easing restrictions if scenes like last night continue to happen.
"They threaten the health of people in Wales and undermine the sacrifices the majority of people have made during this ongoing crisis."
On Monday non-essential retail was allowed to reopen with changes to schools and travel planned for the next two weeks.
Following the incident on the beach South Wales Police tweeted a plea to parents to "check where your children are" after reports of "large numbers of young people" gathered on the coast.
They said two men in their 20s have been arrested and one person was injured.
