It was a dog-walker who was first to alert the emergency services. Civilian protection officers and fire-fighters attended the scene in large numbers, but still struggled to free the syringes from the seaweed in which they had got caught up. Hypodermic syringes had been scattered over an area of 300 yards.
Where the syringes originated remains a mystery, but the hot money is on somebody throwing them off a passing ship. The important port of Zeebrugge is close-by. It's also possible the syringes fell into the water accidentally. Police officers are now on the case to sort out the matter.