When they found Yaguine Koita and Fode Tounkara in the landing gear compartment of a Sabena Airbus, the dead boys, aged 15 and 14, had their arms wrapped around one another. They knew the journey from Guinea-Conakry to Brussels would be cold at 10,000 metres - around minus 50s0]C - so both boys wore layers of pullovers and trousers. On their feet, however, they had only plastic sandals.

The boys also knew that they would probably not survive the journey, and one of them clutched to his heart a letter addressed to "Excellencies, Messieurs the members and leaders of Europe". Written in French by Yaguine - who appears to have planned the escape - the heart-rending plea with its grammatical and spelling errors has been widely published in France and Belgium.

They wanted to talk about "the suffering of us, the children and young of Africa", Yaguine wrote. "We beg of you for the love of your beautiful continent . . . for the love and the friendship of God our creator, the Almighty, who gave you good experiences, wealth and power, to build and organise our continent."

Appealing to the "solidarity and kindness" of Europeans, the 15-year-old stowaway added: "Help us. We suffer enormously in Africa."

A correspondent for Le Monde who learned that Fode Tounkara lived with 11 family members in a 20 square-metre windowless shack with a corrugated iron roof, a broken cement floor, no water and no electricity. His school resembled a barn and had no books.

Yaguine Koita's father Limane, an unemployed radio and television repairman, had enrolled Yaguine in a private school that was scarcely better, Yimbaya College, situated at the end of the landing strip at Conakry airport. Yimbaya is so over-crowded that its 3,200 students attend classes in shifts.

It was probably there that Yaguine thought of sneaking onto a plane bound for Europe. The boys are believed to have climbed into the landing gear compartment after nightfall on July 28th.

Because Sabena inspected its landing gear only once every three weeks, their remains were not discovered until August 2nd by a mechanic in Brussels, alerted by the smell of putrefaction. Yaguine Koita's older sister died of typhoid. His father Limane did not have enough money to pay Yaguine's school fees, so the boy rented to local children the bicycle his mother had sent him from France.

Yaguine was obsessed by the need for education and gave French lessons to younger children. He sent audio-cassettes to his half-sisters in a working class suburb of Paris, telling them, "You must learn if you want to live well."

The preoccupation with learning runs through Yaguine's posthumous letter.

"We have schools in Guinea, but a great lack of education," he wrote. "Except in private schools . . . but you need a lot of money and our parents are poor. So if you see that we have sacrificed ourselves and risked our lives, it is because we suffer too much in Africa and we need you to fight poverty and put an end to war."

The letter ends with a plea for forgiveness, "for daring to write this letter as you are great personages to whom we owe a great deal of respect . . ."

It is signed by "two Guinean children".

On July 28th, Yaguine told his father he was going to visit his maternal grandmother in downtown Conakry. The following day, his brother Ibrahim found Yaguine's farewell letter to his father.

"It's impossible here, nothing can go right," the boy wrote. "If I stay, we shall be miserable until we die. I'd rather leave to try to study elsewhere."

A practising Muslim, Yaguine asked his father to forgive him and to pray for him.

Yaguine's mother, Saran Doumbouya, left west Africa in 1992 for France, where she remarried. She works in old people's homes in the Paris region.

"Like all children in Africa, he dreamed of Europe," Mrs Doumbouya told Le Parisien newspaper before she accompanied the boys' coffins, wrapped in plain jute sacks, on a Sabena flight back to Conakry.

At their funeral on August 8th, the friends of Yaguine and Fode wore white T-shirts emblazoned with their photographs and the words, "The Martyrs of Africa". The families wanted to bury them in their poor neighbourhood of Yimbaya, but the government of Lansana Conte insisted the ceremony take place in Conakry's biggest mosque, and that they be buried downtown.

Mr Conte seized power in 1985. France, the former colonial power, has given Conakry Ffr6 billion (£720,288 million) over the past decade - without obtaining the slightest democratic concession from Mr Conte - and without giving any hope to children like Yaguine and Fode.