Three civilians have been killed and two wounded by an explosive device while swimming in the Black Sea in the Ukrainian southern region of Odesa, local police said on Monday, News.az reports citing Ukrinform

It said the accident happened on Sunday when several people working on a construction site ignored barriers and warning signs on the beach and went swimming in the sea in the Belhorod-Dnistrovskyi district.

"In the water, as a result of an explosion of an unknown object, three men aged 25, 32 and 53 years old ... were killed," the police said in a written statement.

It added that another man and a woman had been wounded.

This summer Ukrainian authorities closed sea beaches because of mines or artillery shells because of the war with Russia and shelling by Russian forces.