While tank crews camped lazily on the side of the road, ready to rumble if called into action, there was excitement in the air as thousands of schoolchildren came thronging through broken school gates at the end of March, desperate to start learning again. Nothing symbolised the feeling that at last there was a future beyond fighting than the sight of children packed into smashed-up classrooms, sitting cross-legged in neat rows, straining to hear their teacher.

At Soofi Islam School in central Kabul, for instance, few of the classrooms had ceilings, none had windows to keep out the scouring dust and wind and most had gaping holes in the walls.

At Habibia Secondary School, every foot of the rendering was pock-marked with bullet holes and there were shell holes on every floor bigger than the pupils. Parts of the playground were out of bounds because they had not been checked for unexploded shells and mines. In any other country it would have been closed as a major safety hazard but Habibia was packed with 2,600 pupils a day, six days a week.

'When they drove the Taleban out, I came back to school,' said Grade Ten student Hussein Sultani, 21, who spent four years as a refugee in Iran. 'But we have no glass in the windows, no chairs, no tables and we sit on the floor.'

Today Habibia looks like a brand new secondary thanks to its new rendering and pink walls. And Soofi Islam is housed in a new building. But they are the lucky ones, as only about one in eight damaged schools has been repaired.

The more likely reality that about two million Afghan children will face can be found in Salang valley, two hours drive north of the capital.

When the new academic year begins later this month, hundreds of schoolchildren will begin their daily hour's trek from cliff-hugging mountain hamlets and pick their way across precipitous slopes to the road to Uzbekistan.

There they will sit on stones and logs in a circle, shivering in anoraks, waiting for the first lesson to begin at Ahangaran School and the teacher will shout to be heard above the noise of passing trucks.

'If you were a father would you send your child to our school?' asked Mahmood, the head teacher.

There are 19 schools in this district but on the last count only three of them had buildings, one had only tents and the rest held classes outdoors. It's a story repeated across a country in which more than two decades of fighting left education starved of investment and 30 per cent of school buildings destroyed.

According to a report published by Oxfam, more than half of Afghan children - about seven million - are still not at school. And that is despite a 500 per cent increase in enrolment in the past six years, fuelled by the return of 4.4 million refugees from neighbouring countries. Currently 51 per cent of boys and 21 per cent of girls are enrolled.

There are plans for dramatic improvements. Afghanistan's millennium development target is to enrol every boy and girl by 2015.

This would mean getting 75 per cent of boys and 60 per cent of girls into school by 2010, when a new curriculum will be operating.

Curricula for four out of nine grades have been completed and 6.2 million textbooks are being distributed. But within four years the aim is to put in place a scheme, such as a national testing system, to assess pupils' learning. Currently the only testing carried out is for university entrance.

The target is for 70 per cent of teachers to pass a competency test. This is ambitious in a country where only one in seven staff are qualified and most have never been to secondary school. When 200 primary teachers were asked to sit the same exams as their students in 2005, only 10 passed.

Grace Ommer, head of Oxfam Great Britain in Afghanistan, said: 'Educating Afghanistan's children is crucial to improving their lives and rebuilding the country. But poverty, crippling fees and huge distances to the nearest school prevent parents sending their children to school.'

Those children who are lucky enough to be in school must endure untrained teachers, inadequate buildings and poor textbooks. 'If Afghanistan is to meet its aims for primary and secondary education, there must be a dramatic increase in aid to the government from rich countries,' Ms Ommer said.

The government controls 97 per cent of schools but relies on aid to fund them, particularly from the United States and World Bank. The latter pays 55 per cent of salaries.

Oxfam believes 53,000 more primary teachers are needed now and an additional 64,000 primary teachers will be needed to cater for the expected rise in pupil enrolment in the next five years. But of 37 planned teacher training institutions only 22 are operating.

A stop-gap four-week intensive in-service course has been developed for the country's teachers but has yet to be rolled out nationally. At Soofi Islam, teachers complained that salaries were so low they could not afford the bus fares to school. Nationally teachers earn US$50 a month on average but in some provinces it is as low as US$38.

It is a measure of how the government is struggling to develop the capacity to manage the system that up to 20,000 teachers are thought to be ghost employees, collecting a salary but not turning up for work. Oxfam estimates a national database and monitoring system could save enough money to pay for 30,000 extra teachers.

Despite the rising intake, schools are haemorrhaging pupils every year, with only 45 per cent completing primary school. The problem is worse for girls. In seven provinces more than 20 per cent of girls who enrolled had not attended at all.

Many of these provinces are in the south, where Nato troops are trying to pin down and push back Taleban forces. Schools have become soft targets for groups trying to destabilise the country. They are burning down schools, threatening teachers and killing some of them.

According to Oxfam, one provincial representative in Kandahar reported that while everyone in Argandob district, a conservative district in the south, wanted to send their daughters to school, once two or three schools were burned down, everybody changed their minds.

Matt Waldman, policy and advocacy adviser at Oxfam International, based in Kabul, said: 'An awful lot more needs to be done. For example US$500 million is needed for school buildings, US$200 million for text books and US$200 million a year to provide a lunchtime snack for children.'

The cost of schooling is another factor in a country where almost six million children are stunted by malnourishment because their parents are too poor to be able to feed them. Needing 70 afghanis (HK$11) to buy a school bag can be enough to force pupils to drop out of school.

For many, paying for uniforms, books, transport, stationery and the shoes children wear out tramping across mountain slopes to school, can make education prohibitive.

'Afghanistan is one of the poorest countries in the world and many families are struggling to make ends meet,' said Mr Waldman.

'So any extra costs which are imposed by education, and these could be the cost of transport or buying books and pencils, will be significant for any family. So that is why we think all efforts should be made to eliminate those kinds of costs.'

A simple midday snack of milk and fortified biscuits - at a cost of US$32 per child per year - could play an invaluable role in bolstering the health of students and the quality of education for Afghanistan's future generations, the non-government organisation says.

The country's education ministry faces a huge problem as millions of refugees return by the truckload from Iran, Pakistan and Tajikistan. The population of Kabul quadrupled in three years after the defeat of the Taleban government.

Oxfam estimates that 7,800 more schools must be built in the next five years, costing US$563 million, not to mention the thousands that need repairs. Seventy-five to 80 per cent of school buildings were damaged or destroyed during 23 years of conflict. But so far only 1,100 have been built or repaired.

Over the past two years 300 schools have been constructed by the National Solidarity Programme and 800 by external organisations often with little or no co-ordination from the Ministry of Education.

'[This] has led to schools being built without provision for teachers to be recruited and no records in the central ministry of where these schools are located,' the report said.

Aid experts say that if Nato wants to win hearts and minds in the war against the Taleban and achieve stability, it should complement its drive to establish security with a concerted push to help the Afghan government put its education system back on track.

As David McGloughlin, head of education at Unicef in Kabul, said: 'We need a better balance between military and development spending.'

Free, Quality Education for Every Afghan Child, Oxfam International