A ‘blood-red’ algae formation in a pond has sparked concern among park-goers this morning.

The algal bloom formed overnight in Lloyd Park, Walthamstow and while the scientific cause remains a mystery it is believed to have been affected by the recent hot weather.

Lloyd Park wardens have been told the bloom is not dangerous to wildlife and will go away of its own accord.

Elisha Jordan, 30, of Carr Road was shocked when she saw the pond's transformation.

She said: “I was really concerned, I thought someone might have died in it and it was blood.

“A lady's small dog went into the pond to get a baguette that had been thrown in for the ducks.

"She went in after it and dragged it out by the scruff of the neck, she definitely thought it could be dangerous.

“I looked closer and saw loads of upside-down flies and thought something must have died in it.

“I ran into the park warden’s office but he calmed me down and said it was an algae that would sort itself out. I was really relieved.

“I think it looks really nice as soon as you know it isn’t dangerous to animals or anyone’s blood.”

Some residents took to Twitter in an attempt to explain the natural phenomenon.

One person believed the red colour was a political act in honour of socialist campaigner William Morris, who lived in the grounds.

Another park-goer believed it was an artistic statement.

Another person was concerned it could have been caused by an act of vandalism or a dead animal.

Waltham Forest council has been approached for comment.