Park swimmers left feeling blue over lake algae warning

Visitors to one of the city's most popular parks have been told not to swim or let their dogs go into a lake after it became filled with a potentially toxic algae.

- by Charles Gray

Blue-green algae has formed on the surface of Waterloo Lake at Roundhay Park in recent days.

Signs have been put up warning people not to go swimming - and to keep their pets out of the water.

The oily substance is described by Defra as "a type of bacteria called cyanobacteria" that can "lead to poor water quality and the production of harmful toxins".