Work never stops at Jamia Sirat-ul-Mustaqeem, a madrassa in a rundown part of Rawalpindi in Pakistan Punjab. After its 20 pupils are in bed, the teachers use Skype to connect to homes in Britain, France, Norway and Sweden, where teenagers attempt to read the unfamiliar Arabic script of the Koran. Many European parents find these online sessions more convenient than after-school classes at the local mosque.

The owner, Maulana Malik Muheisen Shafiq, decided to go round-the-clock four years ago to spread the message of Islam — and subsidise the education of the madrassa’s poorer boys. He charges £35 (Rs.3,100) for three half-hour sessions a week, or £50 for five sessions. “People in Europe spend a huge amount of money seeking knowledge,” he says.

Online Koranic academies range from one-man affairs to call-centre like institutions, with IT managers and teachers working shifts. Competition is getting tougher, says Shafiq who now offers free trial sessions to lure new customers. Parents have no way to check teachers’ background. One former fighter from Lashkar-e-Taiba, which the UN regards as a terrorist front group, teaches from Lahore. But proprietors say parents would quickly realise if teachers strayed beyond reading and reciting the Koran. “We don’t discuss anything related to politics, violence and jihad,” says Shafiq.

Four miles away, in a smarter area, the Zakariyya mosque takes a more traditional approach to spreading the word. It is the Rawalpindi headquarters of the Tablighi Jamaat (TJ) missionary movement, which sends preachers round the world to attract Muslims to the Deobandi movement. The movement seeks to return to the perceived purity of seventh-century Islam and is in some respects similar to the Wahhabism of Saudi Arabia.

Although nearly all Pakistan’s militant groups are within the Deobandi fold, experts disagree on whether TJ poses a security threat. On August 11, the army banned Tariq Jameel, one of its best-known preachers, from speaking at its institutions.

Gulam Rasool, a missionary, has just returned from Indonesia. Britain is one of his favourite destinations, he says: “They’re accepting the true version of Islam in large numbers.” His globe-trotting life of prayer and preaching leaves little time for his family. He is yet to meet his youngest child. When he does see his family, it is usually over Skype.