A crowd of curious children, parents and teachers gathered outside Blaise Primary School after an unidentified object was found on the school field.

Police community support officer Kim Wrixon cordoned off the mystery metal item and urged everyone to keep their distance until the unexpected arrival had been fully investigated.

Head teacher Yvonne Roberts called pupils and staff into an emergency assembly and assured them their safety was paramount.

Caretaker John Llewellyn described how he found the hexagonal object with three twisted spokes sunk into the field yesterday morning. He also revealed to pupils he had seen strange lights and heard noises in the night.

Mr Llewellyn, who lives on the school site in Henbury, said: "The dogs woke me up with their barking. I saw some strange lights and heard some funny noises, then I went back to sleep."

Mrs Roberts urged the children to go back to their classes to discuss what they thought the unidentified object might be.

Year 6 youngsters, aged 10 and 11, had heard television news reports about military documents that reveal a host of unexplained close encounters, and some wondered if the object was a UFO.

Others thought it could be part of a satellite, or a meteor or shooting star, although some suggested it might be a practical joke.

Year 2 children, aged six and seven, eagerly explored the possibility that the object could be part of an alien spaceship or rocket that had exploded and fallen to earth

The pupils will be investigating further ideas during a week of creative activities incorporating music, information technology, literacy and art.