A mysterious trail of blue gliders has had a bumpy landing on the Herefordshire border with Mid Wales.

Claimed to be an anonymous, environmental art project, Der Blaue Glider has deposited toy-sized wooden aircraft outside a series of buildings, public and private, in the Kington area over the past few weeks. But the 'assemble and fly' version delivered secretly to Gladestry Church in Wales School this week has taken a dramatic nose-dive.

Headteacher Hilary Morris said the school was paying no heed to the baffling aircraft. "We need to know about the blue glider and what it represents," she said.

"It sounds as if we're being extra careful, but we haven't got an explanation so how are we to know if it's something genuine?" she said.

Puzzled villagers at Lyonshall have taken note of a 30-inch wingspan glider left at a bus stop, and other models have been left outside the doctors' surgery at Kington and on the steps of Kington Parish Church. This week, a communication arrived at the Hereford Times titled Der Blaue Glider - toying with art.

The sender points out that the project is a self-funded, anonymous, environmental art project based in Herefordshire, Powys and Exeter.

"Its manifesto requires that materials used in the manufacture of its objects should either have been previously discarded (including ready-mades such as synthetics) and involve a process of recycling, or they must be biodegradable," the send states.

"Der Blaue Glider sets out to create thought-provoking, pop-up, public art with an agenda-free, political and social conscience. It is non-exclusive and free of ownership or charge."

Suggesting that the Hereford Times might be a 'go between' for her school and the Gladestry glider, the headteacher said: "They haven't credited us with the facts about it, they haven't sent us a email about it, it was anonymously delivered to us in secret. I'd be happy to get the children involved in assembling the blue glider if we knew about it."