Four men ranging in age from 24 to 50 have died in four separate incidents after getting into trouble in the sea on Sunday, sea rescue workers have confirmed.

One man died near the resort of Wijk aan Zee, one in Zandvoort and two others at the beach in The Hague.

Red flags flew along a huge swathe of the Dutch coast, from Hoek van Holland to Den Helder, on Sunday because of the dangerous currents.  Swimmers were warned not to go into the water above knee height.

A combination of the offshore wind and strong currents had created a ‘very treacherous’ situation, a spokesman for the rescue service told broadcaster NOS. The huge number of people at the beach also made it difficult for lifeguards to patrol properly, the spokesman said.

According to preliminary figures, rescue workers pulled 167 people out of the water, including 37 who were in life threatening situations, news website Nu.nl reported.

Red flags were again in many places along the coast on Monday.