Three rescuers died in a helicopter crash during an overnight mission near the southern French city of Marseille, authorities said.

According to the details, three emergency workers killed in Marseille while two men died in the French Riviera.

Their EC145 helicopter lost radio and radar contact while on a rescue and reconnaissance flight in the Var region.

The three were found dead near the town of Rove, interior minister Christophe Castaner and his secretary of state Laurent Nunez said in a statement.

An investigation was under way to determine the circumstances of the crash.

Two people were killed on Sunday by the floods in the French Riviera, which has been hit by fresh torrential rains a week after extreme weather left six dead.

In the Var region, a shepherd was swept away as he was trying to cross a ford in his 4×4 while tending to his flock.