Four children died after being swept away by the tide while fishing on a riverbank in Canada’s Quebec province, police said Saturday.

“According to preliminary information, a group of eleven people were fishing for capelin on foot along the shore when they were caught by the tide,” the Surete Du Quebec provincial police force told AFP.

The mishap unfolded along the St. Lawrence River near Portneuf-sur-Ner, a municipality northeast of Quebec City

Six of the people were rescued, while five others were missing overnight when authorities were called Friday into Saturday.

A few hours later, four minors over the age of 10 were found unconscious and taken to hospital, where “their deaths were confirmed by a doctor,” the police said.

A search effort including divers and helicopters was ongoing for a man in his thirties who remained missing.