Police were attacked while dispersing a large crowd from a Co Down beach.
Four youths were arrested after officers were called to clear a gathering of around 200 from Ballyholme beach near Bangor last night.
A Police Service of Northern Ireland (PSNI) statement said: "One police officer was injured after she was kicked in the face."
A 17-year-old youth has been charged with offences including assault on police and is expected to appear at Newtownards Youth Court on June 23.
Two others, a woman aged 18 and a 16-year-old boy, have been released to be reported to the prosecutors, while a 15-year-old boy remains in custody.
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 (infection rate) 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."
Today, the Department of Health confirmed one more person who had tested positive for Covid-19 had died, bringing the total toll in Northern Ireland to 522.
A further 13 positive cases of the virus were confirmed, bringing that tally to 4,709.
This weekend there will be increased patrols at beauty spots, resorts and transport hubs, focusing on crowds gathering in breach of the coronavirus regulations, alcohol consumption in public places, speeding and drink driving.
Mr Todd added: "We will continue to engage, explain and encourage people to make the right choices and we will enforce when necessary."
Yesterday, National Trust rangers spent three hours filling 11 bags of rubbish at Bloody Bridge near the Mourne Mountains in Co Down.
Bloody Bridge is a popular starting point for hikes into the mountains as well as coastal strolls.
A fire was also set which had to be attended by fire crews, the National Trust said.
It added: "These beauty spots deserve more of your respect, so please take away the rubbish you bring with you, and with this hot weather, use common sense and don't bring BBQs with you to protect the fragile habitats we work hard to look after."
