All the women working in the information technology division of the Bank of Punjab's headquarters in the western Pakistani city of Lahore wear headscarves tightly wound around their cheeks and chin, framing their faces as they tap at their keyboards. A year or so ago not one covered their heads with the hijab.

"I was the first," says 28-year-old Shumaila, as she waited with some impatience in the city's iStore for her new £800 Apple MacBook to be loaded with the software she had ordered.

"I started reading the Qur'an properly and praying five times a day. No one made me wear the hijab. That would be impossible," she laughs brightly. "I showed the way to the other girls at work."

They are not alone. Though there are no statistics and most evidence is anecdotal, a new wave of interest in more conservative strands of Islam among wealthier and better educated women in Pakistan appears clear.

It is part of a broader cultural and religious shift seen in the country over decades but which observers say has accelerated in the past 10 years.

"The other girls who were working with us left." Shumaila said. "They found the new environment a bit unfriendly."

One indication of the trend is the growing proportion of women within the conservative religious political organisation Jamaat-e-Islami (JI). Syed Munawar Hassan, the leader of JI in Pakistan, said that women made up an increasing proportion of the organisation's 6 million members and 30,000 organisers. "Our women's wing is doing very well," he said. "They are some of our best organisers."

JI, like its counterparts elsewhere in the Islamic world, has traditionally recruited among the lower middle class, swollen in recent decades in Pakistan by rapid urbanisation and economic growth. But the new wave of devotion is now touching the elite in a new way. Al-Huda (The Guidance), an organisation set up in 1994 to spread a new and often rigorous piety among Pakistani women, has gained a foothold among the upper reaches of society.

The group, which critics accuse of encouraging intolerant strands of Islam influenced by those practised in Gulf countries such as Saudi Arabia or Kuwait, has grown from an initial single small centre in Islamabad, the Pakistani capital, to a presence in every city, and is expanding among the Pakistani diaspora abroad.

Members attend intensive courses in Qur'anic studies and Arabic and are directed to do social welfare work, too. Not all enjoy the experience of al-Huda, however.

"I found it very limiting and rigid. But it is very popular among women from very wealthy families that are quite conservative. Recently there are a lot of young women coming to a very traditional Islam. There is a deep desire for learning," said Maha Jehangir, a 30-year-old consultant and former al-Huda member.

Jehangir, who lives in a large house in one of the most exclusive parts of Islamabad, said questions posed by the events of the past decade were particularly important for young women.

"People who grew up within the war on terror are asking, what does it mean to be a Nato ally? Is India our worst enemy? We are bombarded by all this information and there is a deep need for answers. That leads to religious inquiry," Jehangir said.

Many found the answers in conservative strands of religious practice, she said.

Other influences that underpin the new piety among wealthy women include the experience of many Pakistanis who have spent time in the Gulf.

Amna, a 21-year-old business student whose father was a manager for a major firm in Saudi Arabia, said that it was wrong to think that women who were richer or more educated would inevitably be more secular.

"Everything we learn comes from the Qur'an. Maths, computers, banking – the Qur'an contains everything," said Amna, who wears a Saudi-style full veil covering all but her eyes even at the all-female college in Islamabad where she studies.

However, if there is a demand for more rigorous, literalist strands of Islamic practice among wealthy and educated women, there is also an interest in more tolerant varieties.

In Lahore, the al-Mawrid institute is attracting more and more "educated ladies, doctors, professors, housewives who do not know about Islam", says Kaukab Shehzad, a 43-year-old teacher.

The institute, in the wealthy suburb of Model Town, was set up three years ago but had to move after receiving threats from radical scholars, she said. "We read the Qur'an in detail but we discuss other religions too. We were attacked for saying that the niqab [Saudi-style veil] is not justified in the Qur'anic teachings and for arguing against their interpretation of the idea of jihad," she said.

Though solidarity with Muslim communities overseas is encouraged by many conservative practitioners, many of the new devout shun such a global vision and identity. Shumaila, the bank worker and Apple enthusiast, says she is not interested in events in the Middle East: "We've enough going on here."

Jahangir, the former al-Huda member in Islamabad, recently spent two years studying in a religious school of the Deobandi branch of Islam, also followed by the Taliban in Afghanistan. A graduate of both Massachusetts and London Universities, she too said that political activism was of little interest: "I don't try to make sense of the Taliban. I find [them] obscure and irrelevant. For me, [the Deobandi school of Islam] is far more of a route to spirituality than a political ideology."