The incidents were reported during the April 30-May 1 holiday period along the Phuoc Tan-Bai Nga coastal route in Hoa Xuan Commune.
Local forestry officials said the monkeys involved were not wild native animals but individuals previously released into nearby forests after being voluntarily handed over or confiscated in wildlife-related violations.
The monkeys were released into the Deo Ca protected forest area, but some later moved towards nearby coastal roads while searching for food, leading to encounters with residents and visitors.
Local police and ranger forces have been ordered to increase patrols along the coastal route to support visitors and prevent further incidents.
Warning signs reading “Wild monkey area” are also being installed at popular tourist stops, including Bai Tien and Mui Dien.
Authorities have urged visitors to follow “three no’s” guidelines: no close contact, no feeding and no provoking monkeys.
Officials said forestry officers and conservation experts would study the monkeys’ behaviour to develop long-term management plans, including relocating aggressive animals deeper into protected forests away from roads and tourist areas.
Concerned agencies considering penalties for people who intentionally provoke or mistreat monkeys, actions believed to trigger aggressive behaviour.
The Bai Mon-Mui Dai Lanh site, known for offering one of the first sunrise views on mainland Vietnam, attracts large numbers of domestic and international visitors each year.