Four children were found unconscious on a Quebec beach on Saturday morning and were later pronounced dead after being trapped by the tide while participating in a fishing trip, according to the police.

A spokesperson for the Quebec provincial police told CNN that emergency teams were called at 2 a.m. local time on Saturday to Portneuf-sur-Mer, a coastal municipality on the north shore.

Eleven people went missing after embarking on a fishing excursion on foot and being caught by the tide, the spokesperson said. Six out of those 11 people were rescued, and five remained missing overnight.

Around 6 a.m. on Saturday, four children, all over the age of 10, were found unconscious and taken to the hospital, according to the spokesperson. The police later confirmed that the children had died.

A man in his thirties is still missing, according to the Quebec provincial police, and is being searched for with divers, boats, and helicopters.

The Quebec provincial police are investigating the circumstances of the incident, according to the spokesperson.