An 11-year-old pupil from Clifton College preparatory school in Bristol was among the passengers on the Air France jet which disappeared over the Atlantic, the school said today.

Alexander Bjoroy is one of 228 people aboard the missing Air France Airbus A330 aircraft.

A boarder at the school, he was travelling back to Bristol following a half-term break in Brazil.

School head John Milne said: "Clifton College Preparatory School announces with deep regret that a pupil in the school, Alexander Bjoroy, aged 11, was on the Air France flight number AF 447 from Rio de Janeiro bound for Paris on Sunday night which went missing off the coast of North-east Brazil in the early hours of Monday morning.

"Alexander was returning to England from his half-term break.

"Alexander joined the Prep School in January, 2009, and was a well liked and respected boarder who will be sorely missed by his fellow pupils and staff.

"Our deepest sympathies and condolences are with the family in Brazil at this time."

Speaking outside Clifton College today, governor Alison Streatfield-James, who has four children at the school, said she was “absolutely devastated” by news of Alexander’s death.

She said: “Any parent would see this as an utter tragedy.

“It’s a sombre mood at the school today. All the children were informed in assembly and prayers were said. It’s a terrible piece of news to break.

“Children are intelligent, they understand what has happened. All we can do is offer them support in an appropriate way.”

Investigators are today considering several theories as to why a plane carrying 228 people disappeared over the Atlantic Ocean, while Brazilian and French military aircraft scoured a vast swath of ocean between Brazil and the African coast for the Airbus A330.

The wings of the jet were designed and built in Bristol.

Theories included the possibility of Air France Flight 447 being downed by wind and hail in a storm, by lightning, or by a catastrophic combination of factors.

The flight left Rio de Janeiro on Sunday night en route to Paris – only to vanish after issuing an automated message that the electrical system had failed.

Brazil's largest airline, TAM, released a statement late yesterday saying that pilots flying one of its commercial flights from Paris to Rio spotted what they thought was fire in the ocean along the Air France jet's route.

Air Force spokesman Colonel Jorge Amaral told the Agencia Brasil official news service that authorities were investigating the report.

"There is information that the pilot of a TAM aircraft saw several orange points on the ocean while flying over the region," he said.

Two Brazilian air force jets were conducting night searches over the Atlantic early today. Six Brazilian aircraft, including two helicopters, were involved in the search, authorities said.

Authorities have asked any commercial vessels in the area to aid in the search and France sought US satellite help to find the wreckage.

On board the flight were 61 French citizens, 58 Brazilians, 26 Germans, nine Chinese and nine Italians. A lesser number of citizens from 27 other countries also were on the passenger list, including five Britons and two Americans.

Three Irish women, all in their 20s, were on the plane, which had 12 crew. The 216 passengers included a baby and seven children.

French President Nicolas Sarkozy said he told family members of passengers that prospects of finding survivors are "very small".

Brazilian President Luiz Inacio Lula da Silva expressed hope that survivors could be found.

Air France was helping Brazilian relatives of the passengers at the airport in Rio.