Blue balls on British beaches originated from power plant

Nov. 20 (UPI) -- Thousands of mysterious blue rubber balls that washed up on British beaches in recent days originated from a power plant, officials said.

The Tees Valley Wildlife Trust said the spongy rubber balls are used to clean pipes at the Hartlepool Power Station and occasionally spill out into the sea when too much pressure builds up.

"The balls are made of rubber and are not radioactive, but of course they are still a danger to marine wildlife," the trust said in a Facebook post.

The trust is asking members of the public to report locations at which the balls wash up on the beach so energy company EDF, which operates the power plant, can retrieve them.