Three people have been arrested after their plan to aid the escape of an inmate from prison in Las Palmas on the Canary Islands was discovered by police. They planned to use a 13 foot long remote-controlled airship to deliver night vision goggles, climbing gear and camouflage paint to the Italian convict who would then use the equipment to escape from prison.

It is thought the inmate, identified by police as 52 year-old Giulio B, would use the gear to scale down a prison wall at night where a car would be waiting to take him into hiding.

"He would be transported to a foreign country where he would hide out while he waited for false identity documents and would continue to oversee the shipment of drugs to our country," a statement released by Spanish police said.

The three people arrested by police had sent up camp in a camouflaged tent on a hill some 600 metres away from the jail where they spent weeks observing security measures at the prison through powerful binoculars and telephoto lenses. The team of two Spaniards and a Urugauan had set up motion detection sensors around their camp to warn of anyone approaching their stake-out site.

Authorities said they learnt of the plan and intercepted the package containing the inflatable zeppelin when it arrived in the Canary Islands from Bergamo.

The sewer monster is made up of thousands of tiny organisms called bryozoans, or moss animacules, said N.C. State University biologist Thomas Kwak. Invertebrates, they bunch together in colonies and feed with tiny tentacles.

"They can get as big as the size of a watermelon," he said.

They've been known to clog pipes, but Raleigh officials aren't worried, even though bryozoans can move up to 10 centimeters a day. "I don't know if we've seen anything move on its own inside a sanitary sewer line," Public Utilities Director Dale Crisp said.