For Hui women, Islam provides a sense of purpose and community. The Little White Mosque, one of Wuzhong's six all-female mosques, is as much a social club as a place of worship. 'We spend two hours a day here. It's a chance to meet and make friends as well as to practise our religion,' says Wu Lanhong, one of a group of women sitting in the mosque's courtyard. 'We're mostly 40 or over and our children have grown up, so we come here rather than stay at home.'

Having been raised during the Cultural Revolution, when religion was banned, or soon after, many of the women knew little about Islam before they started attending the mosque. 'The old women never got a chance to learn about the Koran or how important it is when they were young,' explains Wang. 'The thing I enjoy the most is teaching them and I know they like learning from me, because they can communicate much better with a woman ahong than with a male one.'

Wang is not quite the equivalent of a male imam. Like other female ahong, she is not allowed to lead the women in salat, the prayers all Muslims must say five times a day. Instead, prayers led by a male imam are transmitted by loudspeaker from a nearby mosque. But Wang gives sermons and teaches from the Koran, a crucial role given many of the women cannot read.

A 2003 survey found 25 per cent of Ningxia's female population were illiterate, as opposed to 10 per cent of the men.

The situation is worse for Hui women. According to a United Nations Development Programme report, literacy rates among the Hui are half those of the majority Han population. In the mountains of southern and central Ningxia, 1.1 million mostly Hui people live beneath China's official poverty line of 668 yuan a year. It is the nation's poorest region and education takes second place to the battle to survive.

All five of the religions tolerated in China - Buddhism, Taoism, Catholicism, Protestantism and Islam - are experiencing a revival as people search for stability and meaning in a country that is changing rapidly. A survey this year by Shanghai's East China Normal University revealed that 31.4 per cent of Chinese over the age of 16, or about 400 million people, considered themselves believers. An estimated 20 million to 35 million of them are Muslims.

But for the Hui, who are the descendants of Arab traders, who started arriving in China in the 7th century, renewing their faith in Islam is a way of re-asserting their unique identity after hundreds of years of assimilation into mainstream Chinese society. Now indistinguishable from the Han, apart from the white skullcaps the men wear and the scarves the women use to cover their heads, religion has become the focal point of life for many Hui. Thousands of young Hui travel abroad to study in Muslim countries. Later this year, 500 Hui from Wuzhong will make the haj pilgrimage to Mecca, or Maijia as the Chinese call it; 10 years ago, only 48 made the journey.

Learning Arabic has become popular; hundreds of language schools have sprung up in Ningxia in recent years. Many mosques teach it and Arabic is one of the most popular courses at Ningxia's universities.

At the Wunan Mosque in Wuzhong, Jin Meihua sits in front of a blackboard covered in script. For the past five years, she has taught a daily Arabic class for women. An impressive figure who was one of 1,000 women from around the world jointly nominated for the 2005 Nobel Peace Prize for work in their community, Jin has been an ahong for six years. At 43, she is the youngest in Wuzhong.

Her students have a far easier time than she did when she was learning Arabic. 'It was 11 years ago.

I heard a male imam speaking in Arabic and decided to study it because it's the language of our religion,' Jin recalls. 'So I went to a class where there were 40 of us at the beginning. But by the end, I was the only one left so I learned on my own. I studied late at night, after my children had gone to bed.'

Like the congregation at the Little White Mosque, most of Jin's students are older women trying to make up for their lack of formal education. 'It's very rewarding to see how their lives become richer and more fulfilled after they start studying for the first time in their lives,' she says. 'Before, they knew absolutely nothing about their religion and had never been given the chance to study anything.'

It is too late for Jin and Wang's students to use Arabic to carve out better lives for themselves but for younger Hui women in Ningxia, learning the language has become one of the principal means of escaping poverty. Demand for Chinese-Arabic translators has surged in recent years as China's economic links with the Middle East have expanded. China's trade with the Arab world was worth about US$50 billion in 2005 and is expected to double by 2015.

With their shared religion and cultural affinity to the Middle East, the Hui are ideally placed to capitalise on the demand for Arabic translators. While boys are needed to work on family farms, many young Hui women are being sent to language schools. 'My parents wanted me to study Arabic so I can become a translator,' says Ji Xiaoli, an 18-year-old student at the Wuzhong Han Qu Arabic School, a boarding school for girls on the outskirts of Wuzhong. 'I enjoy it. It's not too hard, about the same as learning English.'

Ji is one of 75 women aged between 16 and 20 attending the school. With fees of 400 yuan a term, it's an affordable option for poor families. While their Han contemporaries dress in jeans and skimpy tops and meet their boyfriends, the girls at the school wear long dresses over trousers and headscarves, and sleep in bunk beds in simple rooms. They lead a strict life, praying five times daily and fasting during Ramadan, Islam's most important festival. They learn Arabic by studying the Koran for three hours a day.

Despite the emphasis on religion, however, the school's headmistress concedes that her pupils are here for financial, not spiritual, reasons. 'Most of the girls are learning Arabic so they can get good jobs as teachers or translators,' says Wang Xiubin. The school has been open only since 2003. 'When I was young, there were no schools like this in Ningxia; I had to go to Lanzhou [the provincial capital of Gansu] to learn Arabic.'

Some of the girls talk of travelling to Egypt or Pakistan to work. Most though, will stay in China, either in Ningxia or in Xinjiang, the autonomous region in the far west and home to the other large concentration of China's Muslims. But the government's attitude to Xinjiang's 10 million-odd Muslims is very different to their approach to the Hui. Most Muslims in Xinjiang are Uygurs, an Indo-European ethnic minority whose members speak a language similar to Turkish. Many want their own independent state, which they would call East Turkestan.

In contrast, the 9 million Hui across China have been successfully assimilated into the Han population, speak Putonghua and pose no political threat. While the government continues to crack down on what it describes as 'separatists' in Xinjiang and has previously restricted the Uygur's right to worship, the Hui are seen as an asset in China's bid to boost its ties with the Arab world.

Nevertheless, there is little doubt Islamic orthodoxy is on the rise among the Hui. Once known for their lax interpretation of Islam, with many men drinking alcohol and few women covering their heads, the Hui's strengthening links with other parts of the Muslim world have seen them become far more rigid in their customs. 'Now so many Hui people are going abroad to study Islam, it's natural that when they come back they have different views to what they learned here,' says Ma Wanyun, a male imam from Wuzhong who spent three years studying in Libya.

That includes a rising distrust of the United States, something prompted by its involvement in Iraq and the effect it has had in creating anti-Muslim feeling in the west. 'Are you Americans?' was the first question the headmistress of the Wuzhong Han Qu Arabic School asked us when we arrived. Only after we reassured her we weren't did she allow us to talk to her students.

After years of dressing like the Han, Hui women are being encouraged by their female imams to wear traditional Muslim clothing. 'The Koran says women should cover their faces, and although there are differences in our national culture to other Muslim countries, the traditions of our religion are the same and should be observed,' says Jin. 'What I teach the women is that when they go out, the only thing people should be able to see is their face and hands.'

As the Hui become more orthodox, male opposition to the way Hui women are taking advantage of opportunities to improve their lives is growing. 'A lot of men don't like the idea of women coming to an all-female mosque every day or studying the Koran and Arabic. They think we should be at home cooking and looking after the children,' says Jin.

Although such attitudes are more common in the isolated rural areas of Ningxia, all the female imams in Wuzhong have encountered them. 'I have been told by men that women shouldn't be ahong,' says Wang Shuying. And while Wuzhong's male-led mosques are imposing structures with minarets, the all-female mosques are cramped and basic in comparison, as if they were built as an afterthought.

Male prejudice is unlikely to deter the increasing number of Hui women returning to their religious roots. Nor does the spectre of Islamic fundamentalism taking root in China concern the vast majority of them. Instead, they see Islam as an empowering experience. In one of China's most deprived regions, for the first time in Hui history, religion is a potential passport to a better life. Having to wear a headscarf and facing criticism from their menfolk are small prices to pay for that.