With the gradual easing of lockdown restrictions, Italian authorities fear there will be more social gatherings.
Milan mayor Giuseppe Sala reinforced police controls in the Navigli area of Milan to prevent crowds from meeting up.
A large number of people on Thursday threatened to close the entire place down on Friday.
The area has five interconnecting canals around the city centre and is usually a hub for nightlife and some premises are now open for take-aways.
Italy's Adriatic coast
Over on the Adriatic coastline at Bari, it was a similar story with hoards of people on the seafront.
"I can`t stay in my house anymore," said one woman. "I'm retired and alone. I've become depressed and I can`t stand it anymore!"
Already more than 30,201 people have died in the country from COVID-19 and 217,185 are confirmed to have the infection, according to Johns Hopkins University figures.
Marine Police Officers on the beaches at Carcavelos near Lisbon are stopping people from sunbathing.
"You can`t be staying here," said one officer who stopped a couple from sunbathing together. "The beach is only available for physical exercise and nothing else," he added.
Lying in the sun is banned and the beaches are only open for sport activities.
Vanessa Coelho Marine Police Officer said, "Sometimes people feel intimidated when they are alerted in front of others and have a posture that they individually maybe wouldn`t have. We always try to get around the situation and keep calm and take things the best way. Sometimes it isn't an easy task, especially in the aquatic environment, where it is even more difficult to do this control with the distance that is necessary in the water."
But most people in Portugal are following the advice from the authorities but there are always a few who don't respect the regulations.
More than 27,406 people in Portugal are confirmed with the virus and more than 1,126 have died from the disease so far, according to Johns Hopkins University figures.