A man allegedly hit his partner on a packed beach before onlookers dragged him into the sea and pummelled him.
He is also accused of assaulting another woman who he mistook for his wife.
Witnesses said the alleged assault was triggered by jealousy after he saw his partner chatting with another man on the beach.
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In the clip, the suspect apparently struck the mistaken woman across the head, knocking her down in front of numerous beach goers.
She looked up at him in shock as he seemed surprised that he targeted the wrong person.
He then ran into the shallow water and allegedly hit his partner repeatedly in the face.
One bystander pushed him away from the woman.
A man in a baseball cap then struck him from behind as he tried to flee.
At least two other men joined in the fray, apparently battering him in the sea.
The alleged assault took place on Saona Island in the Dominican Republic on Friday (3 Jul).
Dominican tourism police have confirmed they are investigating the case.
Officers are seeking additional witnesses to support the probe, as reported by Need To Know.
No arrests have been made yet.
Saona Island is a tropical holiday destination located off the coast of Punta Cana.
It is renowned for its pristine white-sand beaches, crystal-clear waters, and status as a protected area within Cotubanamá National Park.
The island attracts thousands of tourists daily for boat excursions, snorkelling, and relaxing beach days.
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