The sun brought a surge of day-trippers to Northern Ireland's north coast on Sunday, as the relaxation of months of lockdown rules began to lift the public mood.
Beaches at Portrush and Portstewart were packed, while in the towns cars jammed the narrow streets.
Police were on the alert amid concerns about potential anti-social behaviour from alcohol-fuelled youths enjoying a taste of freedom.
Causeway Coast and Glens PSNI said it had increased the police presence around train stations on the north coast, following reports of large numbers of young people with alcohol travelling to Portrush.
A gathering of 50 youths on Ramore Head was broken up and alcohol seized, the PSNI reported.
"It is clear from senior health advisors and senior political leaders that the risks of the pandemic are not yet behind us," a PSNI spokesperson said.
"Political leaders, supported by senior medical advisors, continue to have health protection legislation in place and the PSNI will continue to utilise our four 'Es' approach of engaging, explaining and encouraging compliance and, where and when necessary, move to enforcement to keep everyone safe."
The police warning comes as Northern Ireland looks forward to a further easing of lockdown restrictions later this week.
Crowds are likely to return to the coast next weekend, as self-contained tourist accommodation, such as caravans and rented holiday homes, will be allowed to operate.
'Non-essential' retail is due to reopen from this coming Friday, as will cafes, coffee shops, restaurants, social clubs and beer gardens - for outdoor service only.
Indoor hospitality is not expected to reopen until May 24.
Health Minister Robin Swann said on Sunday that the Covid-19 vaccination programme is being extended to people aged over 35.
"I know this will be welcome news for those in this age group and I would urge people to book a vaccination appointment as soon as possible," he said.
"This week we will see further easing of restrictions with the re-opening of non-essential retail, gyms, leisure facilities and some tourist accommodation.
"These easements have only been possible because of the success of the vaccination programme, coupled with the actions of the general public."
The Health Minister appealed for everyone in the target group to book an appointment to be vaccinated as soon as possible.
"I know there are some younger people that think they don't need the vaccine but we have seen what this virus can do. So please protect yourself and get the vaccine," he said.
"Vaccination is absolutely vital in helping us move through this pandemic.
"There is no doubt that there are people in Northern Ireland alive today because they have been vaccinated," he said.
No further Covid-19-related deaths were reported on Sunday in Northern Ireland from the previous 24 hours, with the total number of deaths remaining at 2,142. Another 73 people tested positive for coronavirus.
On Sunday morning, there were 60 confirmed Covid-19 patients in hospital, five of whom were in ICU.
In total, 905,736 people in Northern Ireland have received one dose of a Covid-19 vaccine, while 342,195 have received two doses.