Giant peaks of foam have formed in a popular water feature, causing chunks of froth to float out onto the road.
The fountain in the South Marine Park in South Shields has been left looking like a giant meringue, with chunks of foam floating off into roads nearby.
Park visitors suspect a soapy substance was poured into the fountain's pool last night, with the force of the falling water causing it to form giant mounds of froth.
One man said: "I was coming up Sea View Terrace when I saw foam floating in the air, and then a huge chunk of it sitting in the road.
"I thought 'hang on?' and knew it must be coming from the fountain in the park. When I went round it was full of foam."
We have asked South Tyneside Council for a comment and are waiting for a response on what the situation is with the water feature.
Pouring washing-up liquid into public fountains used to be a popular prank in decades past.
Water features outside South Shields Town Hall were often victim to such acts in the 1980s and 1990s.