Police have had to deal with a large gathering of more than 200 people at Ballyholme beach and one officer was injured after she was kicked in the face.
Officers came under attack from some sections of the crowd, who had gathered at the beach in the Bangor area of Co Down despite the ongoing need for social distancing measures due to coronavirus.
Four teenagers were arrested.
A 17-year-old boy has since been charged with a number of offences, including assault on police and is expected to appear before Newtownards Youth Court on 23 June.
An 18-year-old girl and 16-year-old boy have been released pending reports to the Public Prosecution Service, and a 15-year-old boy remains in police custody.
We will continue to engage, explain and encourage people to make the right choices and we will enforce when necessary.
PSNI Assistant Chief Constable Alan Todd said: “I understand that as time goes on, and with the current spell of good weather, some people may be tempted to get out and about and make the most of the sunshine.
“However, as a police service, our key role is to support our public health colleagues and the Northern Ireland Executive to ensure we all play our part in stopping the spread of the virus and help save lives.
“The latest data available shows that the R-number, which was flattening/falling, has actually increased again as restrictions have been eased.
“This means that every one of us needs to make informed and sensible decisions about our conduct over the coming days to ensure that we are protecting our own health and the health of others.”
Patrols have been stepped up over the weekend, particularly around beauty spots, resorts, and transport hubs.
Police say they will be focusing on “the issues of crowds gathering in breach of Regulation 6 of the Health Protection Regulations, alcohol consumption in designated public places, and road safety - particularly speeding and drink driving”.
ACC Todd added: “The public should be well aware of the advice from our public health partners and the Government about social distancing and movement and, on that basis, we would encourage people not to drive to local beauty spots or popular destinations for their daily exercise, as others may have the same idea and social distancing may not be achievable.
“Each and every one of us has a personal responsibility to follow the NI Executive regulations and do everything we can to stop the spread of Covid-19.”
Meanwhile, the latest data from the Department of Health shows that one more person who tested positive for coronavirus in Northern Ireland has died in the last 24 hours.
That takes the total to 522, but the final tally will be significantly higher.
Data from the NI Statistics and Research Agency, which is recorded differently, but the total at 716 as of 22 May.
Coronavirus: Everything you need to know